Surgical Resolution of Bilateral Hypertrophy of Masseter Muscle Through Intraoral Approach.

Science.gov (United States)

Trento, Guilherme Dos Santos; Benato, Leonardo Silva; Rebellato, Nelson Luis Barbosa; Klüppel, Leandro Eduardo

2017-06-01

Masseter muscle hypertrophy is an untypical anomaly with no definite cause and its diagnosis is easily completed through physical examination and imaging examinations. In some cases, patient may report signs and symptoms of well-localizated pain. However, it is generally asymptomatic and patient's chief complaint is about esthetic because of facial asymmetry. In this case, surgery is carefully indicated. The aim of this article is to report a case of a male patient with no painful and functional complaints but an important unease over his facial asymmetry. Patient underwent surgery involving bilateral resection of mandibular angles and unilateral resection of masseter muscle through intraoral approach. Surgical approaches and techniques rely heavily on surgeon. There are few reports in the literature about this anomaly, but those available present several techniques. The surgeon's dexterity and knowledge become extremely important, whereas this procedure is essentiallyesthetic.

Inhibition of muscle spindle afferent activity during masseter muscle fatigue in the rat.

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Brunetti, Orazio; Della Torre, Giovannella; Lucchi, Maria Luisa; Chiocchetti, Roberto; Bortolami, Ruggero; Pettorossi, Vito Enrico

2003-09-01

The influence of muscle fatigue on the jaw-closing muscle spindle activity has been investigated by analyzing: (1) the field potentials evoked in the trigeminal motor nucleus (Vmot) by trigeminal mesencephalic nucleus (Vmes) stimulation, (2) the orthodromic and antidromic responses evoked in the Vmes by stimulation of the peripheral and central axons of the muscle proprioceptive afferents, and (3) the extracellular unitary discharge of masseter muscle spindles recorded in the Vmes. The masseter muscle was fatigued by prolonged tetanic masseter nerve electrical stimulation. Pre- and postsynaptic components of the potentials evoked in the Vmot showed a significant reduction in amplitude following muscle fatigue. Orthodromic and antidromic potentials recorded in the Vmes also showed a similar amplitude decrease. Furthermore, muscle fatigue caused a decrease of the discharge frequency of masseter muscle spindle afferents in most of the examined units. The inhibition of the potential amplitude and discharge frequency was strictly correlated with the extent of muscle fatigue and was mediated by the group III and IV afferent muscle fibers activated by fatigue. In fact, the inhibitory effect was abolished by capsaicin injection in the masseter muscle that provokes selective degeneration of small afferent muscle fibers containing neurokinins. We concluded that fatigue signals originating from the muscle and traveling through capsaicin-sensitive fibers are able to diminish the proprioceptive input by a central presynaptic influence. In the second part of the study, we examined the central projection of the masseter small afferents sensitive to capsaicin at the electron-microscopic level. Fiber degeneration was induced by injecting capsaicin into the masseter muscle. Degenerating terminals were found on the soma and stem process in Vmes and on the dendritic tree of neurons in Vmot. This suggests that small muscle afferents may influence the muscle spindle activity through

Properties of tonic episodes of masseter muscle activity during waking hours and sleep in subjects with and without history of orofacial pain.

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Mude, Acing Habibie; Kawakami, Shigehisa; Kato, Seiya; Minagi, Shogo

2018-04-01

To provide a scientific data related to the tonic activity of masseter muscle in subjects with and without history of orofacial pain during their normal daily life. Thirty-three subjects were divided into two groups, a pain history group (PHG) and a non-pain history group (non-PHG), based on their responses to the Research Diagnostic Criteria for Temporomandibular Disorders questionnaire. After excluding four subjects with incomplete recordings, full-day masseter muscle surface EMGs of 29 subjects (10 men, 19 women; mean age 24.1 years) were analyzed. Tonic episode (TE) was defined as continuous EMG activity with a duration at least 2s with intensities above twice the baseline noise level. TEs were classified into 6 strength categories (40% of the maximum voluntary clenching (MVC)). The mean duration of activity observed in the non-PHG+2 SD was adopted as a cutoff for identifying sustained TE. During waking hours, the incidence of sustained TEs was significantly higher in the PHG than in the non-PHG (porofacial pain and the intensity range of 7.5-25% MVC would be an important range for future clenching studies. Copyright © 2017. Published by Elsevier Ltd.

Role of TRPV1 and ASIC3 channels in experimental occlusal interference-induced hyperalgesia in rat masseter muscle.

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Xu, X X; Cao, Y; Ding, T T; Fu, K Y; Li, Y; Xie, Q F

2016-04-01

Masticatory muscle pain may occur following immediate occlusal alteration by dental treatment. The underlying mechanisms are poorly understood. Transient receptor potential vanilloid-1 (TRPV1) and acid-sensing ion channel-3 (ASIC3) mediate muscle hyperalgesia under various pathologic conditions. We have developed a rat model of experimental occlusal interference (EOI) that consistently induces mechanical hyperalgesia in jaw muscles. Whether TRPV1 and ASIC3 mediate this EOI-induced hyperalgesia is unknown. Rat model of EOI-induced masseter hyperalgesia was established. Real-time polymerase chain reaction, Western blot and retrograde labelling combined with immunofluorescence were performed to evaluate the modulation of TRPV1 and ASIC3 expression in trigeminal ganglia (TGs) and masseter afferents of rats after EOI. The effects of intramuscular administration of TRPV1 and ASIC3 antagonists on the EOI-induced hyperalgesia in masseter muscle were examined. After EOI, gene expressions and protein levels of TRPV1 and ASIC3 in bilateral TGs were up-regulated. The percentage of ASIC3- (but not TRPV1-) positive neurons in masseter afferents increased after EOI. More small-sized and small to medium-sized masseter afferents expressed TRPV1 and ASIC3 separately following EOI. These changes peaked at day 7 and then returned to original status within 10 days after EOI. Intramuscular administration of the TRPV1 antagonist AMG-9810 partially reversed this mechanical hyperalgesia in masseter muscle. No improvement was exhibited after administration of the ASIC3 antagonist APETx2. Co-injection of AMG-9810 and APETx2 enhanced the effect of AMG-9810 administration alone. Peripheral TRPV1 and ASIC3 contribute to the development of the EOI-induced mechanical hyperalgesia in masseter muscle. © 2015 European Pain Federation - EFIC®

[Experimental occlusal interference induces the expression of protein gene products and substance P in masseter muscles of rats].

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Cao, Ye; Li, Kai; Fu, Kai-yuan; Xie, Qiu-fei

2010-02-18

To investigate the peripheral mechanism by studying the histological changes of masseter muscles using HE stains and substance P (SP) and protein gene product 9.5 (PGP9.5) immunohistochemical stains. Fifteen male Sprague-Dawley were randomly assigned into occlusal interference group (n=12) and control group (n=3). In occlusal interference group, 0.4 mm thick crowns were bonded to the rats' first molar of the maxillary. In the control group, rats were anesthetized and mouths were forced open for about 5 min but restorations were not applied. 1, 5, 10, and 21 d after 0.4 mm occlusal alteration treatment, mechanical pain thresholds of bilateral masseter muscles were quantitatively measured by modified electronic anesthesiometer in control group and occlusal interference group. The rats were euthanized by transcardiac perfusion after deep anesthetization at different time points. The paraffin sections of masseter muscles were made and processed for HE, SP, and PGP9.5 immunohistochemical staining. Decreased head withdrawal threshold to mechanical pressure was detected in masseter muscles on both sides following occlusal interference. Histological stains of masseter muscles presented intact following occlusal interference, and no inflammatory cells were observed in both sides. Intensely stained PGP9.5 was observed at 1 d in occlusal interference groups and maintained until the end of the experiment. SP expression was the most obviously increased at 5 d in both sides and gradually decreased to the level of control. Experimental occlusal interference-induced masticatory muscle pain is associated with peripheral sensitization of nociceptive neurons rather than muscle damage and inflammation.

Prolonging the duration of masseter muscle reduction by adjusting the masticatory movements after the treatment of masseter muscle hypertrophy with botulinum toxin type a injection.

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Wei, Jiao; Xu, Hua; Dong, Jiasheng; Li, Qingfeng; Dai, Chuanchang

2015-01-01

Botulinum toxin type A (BTX-A) is widely used for the clinical treatment of masseteric hypertrophy. Until now, few reports have discussed how to prolong the duration of its effectiveness. This study evaluated that purposely adjusting the masticatory movements is possible of postponing the masseter muscle rehypertrophy. Ninety-eight patients were randomly and equally divided into 2 groups, and 35 U BTX-A per side was injected into the masseters. The thickness and volume of the masticatory muscles were measured by ultrasound and computerized tomography, respectively. Patients in Group 1 were instructed to strengthen their masticatory effort during the denervated atrophic stage of the masseter (the interval was evaluated by real-time ultrasound monitoring), whereas patients in Group 2 were not given this instruction. When the masseter muscle began to recover, patients in both groups were instructed to reduce their chewing. The duration of the masseter muscle rehypertrophy was significantly prolonged in Group 1 patients. The thickness and the volume of the other masticatory muscles were significantly increased in Group 1 but were either slightly decreased or insignificantly different in Group 2. Purposely strengthening masticatory muscle movement during the denervated atrophic stage of the masseter can prolong the duration of masseter rehypertrophy.

Histological study of rat masseter muscle following experimental occlusal alteration.

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Nishide, N; Baba, S; Hori, N; Nishikawa, H

2001-03-01

It has been suggested that occlusal interference results in masticatory muscle dysfunction. In our previous study, occlusal interference reduced the rat masseter energy level during masticatory movements. The purpose of this study was to investigate the histological alterations of rat masseter muscles following experimental occlusal alteration with unilateral bite-raising. A total of eight male adult Wistar rats were equally divided into control and experimental groups. The experimental rats wore bite-raising splints on the unilateral upper molar. However, 4 weeks after the operation, the anterior deep masseter muscles were removed and then stained for succinic acid dehydrogenase (SDH), haematoxylin eosin (HE) and myofibrillar ATPase. Most of the muscle fibres in experimental rats remained intact, although partial histological changes were observed, such as extended connective tissue, appearance of inflammatory cells in the muscle fibres and existence of muscle fibres with central nuclei and central cores. Moreover, the fibre area-fibre frequency histograms of experimental muscle indicated a broad pattern than that of controls. These results indicated that occlusal interference caused histological changes in masseter muscles and that this may be related to the fact that the masseter energy level was reduced during masticatory movements in unilateral bite-raised rats.

Esterase profile of human masseter muscle

DEFF Research Database (Denmark)

Kirkeby, S; Moe, D; Vilmann, H

1988-01-01

The esterase profile of fresh human masseter muscle was investigated by use of histochemistry and electrophoresis. The histochemical methods included reactions for alpha-naphthyl esterase, myofibrillar ATPase, reverse myofibrillar ATPase and succinic dehydrogenase. In frozen sections of the muscle...... the coloured reaction product for esterases was present both as a diffuse sarcoplasmic coloration and as distinct granules. The intensity of diffuse reaction was used to classify the muscle fibres as strongly, moderately and weakly reacting. The fibres with strong esterase activity belonged to Type I and ii......C. iM and Type II A fibres showed a moderate esterase reaction and Type II B fibres had a low activity. The electrophoretic gels stained for esterase activity showed that the human masseter muscle possesses a slow migrating double band with high enzyme activity and a cascade of faster migrating...

Masseter muscle thickness in unilateral partial edentulism: An ultrasonographic study

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S Sathasivasubramanian

2017-01-01

Full Text Available Introduction: Teeth and facial muscles play a very important role in occlusal equilibrium and function. Occlusal derangement, seen in unilateral partially edentulous individuals, has an effect on masseter muscle anatomy and function. The present study aims to evaluate masseter muscle thickness in unilateral partial edentulism. Patients and Methods: Institutional ethics committee approval was obtained before the commencement of the study. The study involved patients who routinely visited the Department of Oral Medicine and Radiology, Sri Ramachandra University. The study sample included 27 unilateral edentulous patients (Group E and 30 controls (Group C. The masseter muscle thickness was evaluated using high-resolution ultrasound real-time scanner (linear transducer − 7.5–10 MHz at both relaxed and contracted states. Statistical Analysis Used: The results were analyzed using paired t-test and independent t-test. Duration of edentulism and muscle thickness was assessed using Pearson's correlation coefficient. Results: The study patients' age ranged between 25 and 48 years (mean – 36 years. The comparative evaluation of masseter muscle thickness between the dentulous and edentulous sides of experimental group was statistically significant (P < 0.05. However, no statistically significant difference in masseter muscle thickness was found between the dentulous side of control and experimental groups. The correlation between the duration of partial edentulism and muscle thickness was statistically insignificant. Conclusion: The study proves masseter atrophy in the edentulous side. However, since the difference is found to be marginal with the present sample, a greater sample is necessary to establish and prove the present findings as well as to correlate with the duration of edentulism. Further studies are aimed to assess the muscle morphology after prosthetic rehabilitation.

THE CAPILLARY PATTERN IN HUMAN MASSETER MUSCLE DURING AGEING

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Erika Cvetko

2013-10-01

Full Text Available The effect of ageing on the capillary network in skeletal muscles has produced conflicting results in both, human and animals studies. Some of the inconsistencies are due to non-comparable and biased methods that were applied on thin transversal sections, especially in muscles with complicated morphological structures, such as in human masseter muscle. We present a new immunohistochemical method for staining capillaries and muscle fibres in 100 µm thick sections as well as novel approach to 3D visualization of capillaries and muscle fibres. Applying confocal microscopy and virtual 3D stereological grids, or tracing capillaries in virtual reality, length of capillaries within a muscle volume or length of capillaries adjacent to muscle fibre per fibre length, fibre surface or fibre volume were evaluated in masseter muscle of young and old subjects by an unbiased approach. Our findings show that anatomic capillarity is well maintained in masseter muscle in old subjects; however, vascular remodelling occurs with age, which could be a response to changed muscle function and age-related muscle fibre type transformations.

Hipertrofia benigna do músculo masseter Benign masseter muscle hypertrophy

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Daniel Zeni Rispoli

2008-10-01

Full Text Available A hipertrofia idiopática do músculo masseter (HIM é uma patologia pouco freqüente e de causa desconhecida. Alguns autores correlacionam tal condição com hábitos de mascar gomas, disfunção da articulação temporomandibular (ATM, hipertrofias congênitas e funcionais, e distúrbios emocionais (nervosismo e ansiedade. A maioria dos pacientes queixa-se da alteração estética decorrente da assimetria facial, também chamada "face quadrada", no entanto, sintomas como trismo, protrusão e bruxismo também podem ocorrer. Os objetivos deste estudo foram: relatar um caso de HIM e descrever a sintomatologia e o tratamento realizado. O paciente relatava aumento bilateral na região do ângulo da mandíbula de evolução lenta e progressiva. Negava dor ou desconforto, porém se queixava de otalgia bilateral, trismo noturno e ansiedade. Ao exame físico, observou-se hipertrofia bilateral de masseter sem alterações inflamatórias no local. Foi indicado tratamento cirúrgico com abordagem extra-oral. Exames complementares são indicados na dúvida diagnóstica. A conduta terapêutica varia de conservadora a cirúrgica, sendo que esta depende principalmente da experiência e da habilidade do cirurgião.Idiopathic hypertrophy of the masseter muscle is a rare disorder of unknown cause. Some authors associate it with the habit of chewing gum, temporo-mandibular joint disorder, congenital and functional hypertrophies, and emotional disorders (stress and nervousness. Most patients complain of the cosmetic change caused by facial asymmetry, also called square face, however, symptoms such as trismus, protrusion and bruxism may also occur. The goals of the present investigation were: to report a case of idiopathic masseter hypertrophy, describe its symptoms and treatment. The patient reported bilateral bulging in the region of the mandible angle, of slow and progressive evolution. He did not complain of pain or discomfort, however there was bilateral

Association of occlusal interference-induced masseter muscle hyperalgesia and P2X3 receptors in the trigeminal subnucleus caudalis and midbrain periaqueductal gray.

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Sun, Shuzhen; Qi, Dong; Yang, Yingying; Ji, Ping; Kong, Jingjing; Wu, Qingting

2016-03-02

P2X3 receptor plays a role in nociception transmission of orofacial pain in temporomandibular disorder patients. A previous study found that P2X3 receptors in masseter muscle afferent neurons and the trigeminal ganglia were involved in masseter muscle pain induced by inflammation caused by chemical agents or eccentric muscle contraction. In this study, we attempted to investigate changes in P2X3 receptors in the trigeminal subnucleus caudalis (Vc) and midbrain periaqueductal gray (PAG) in relation to the hyperalgesia of masseter muscles induced by occlusal interference. Experimental occlusal interference by crown application was established in 30 rats and another 30 rats were treated as sham controls. On days 1, 3, 7, 14, and 28 after crown application, the mechanical pain threshold was examined by von-Frey filaments. The expression of the P2X3 receptor in Vc and PAG was investigated by immunohistochemistry and quantitative PCR. We found that mechanical pain threshold of bilateral masseter muscles decreased significantly after occlusal interference, which remained for the entire experimental period. The mRNA expression of the P2X3 receptor increased significantly and the number of P2X3R-positive neurons increased markedly in Vc and PAG accordingly. These results indicate that the upregulated expression of P2X3 receptors in Vc and PAG may contribute toward the development of orofacial pain induced by occlusal interference and P2X3 receptors in the PAG may play a key role in the supraspinal antiociception effect.

Persistent orofacial muscle pain: Its synonymous terminology and presentation.

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Spierings, Egilius L H; Mulder, Maxim J H L

2017-09-01

The purpose of the present paper is to describe the presentation of persistent orofacial muscle pain, also commonly referred to as myofascial temporomandibular disorder. In this practice survey, the authors reviewed the demographic and clinical features of 34 patients who were evaluated and diagnosed personally. The majority of the 34 patients were women (82.4%), and their age at consultation averaged 44.6 ± 12.6 (SD) years. The median pain duration was 4.0 years (range: 0.2-34 years). In 97.1% of patients, the pain occurred daily and continuously, and in 51.9% it was unilateral. Chewing or eating made the pain worse in 50% of the patients, and talking in 29.4%. On examination, tightness of the masseter muscle(s) was present in 58.8%, and tenderness in 58.8%. Persistent orofacial muscle pain mostly affects women, generally occurs daily and continuously, and is equally often unilateral and bilateral. Chewing, eating, and talking are the most common aggravating factors, and tightness or tenderness of the masseter muscle(s) is often found on examination.

Muscle Fatigue in the Temporal and Masseter Muscles in Patients with Temporomandibular Dysfunction

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Krzysztof Woźniak

2015-01-01

Full Text Available The aim of this study is to evaluate muscle fatigue in the temporal and masseter muscles in patients with temporomandibular dysfunction (TMD. Two hundred volunteers aged 19.3 to 27.8 years (mean 21.50, SD 0.97 participated in this study. Electromyographical (EMG recordings were performed using a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany. Muscle fatigue was evaluated on the basis of a maximum effort test. The test was performed during a 10-second maximum isometric contraction (MVC of the jaws. An analysis of changes in the mean power frequency of the two pairs of temporal and masseter muscles (MPF% revealed significant differences in the groups of patients with varying degrees of temporomandibular disorders according to Di (P<0.0000. The study showed an increase in the muscle fatigue of the temporal and masseter muscles correlated with the intensity of temporomandibular dysfunction symptoms in patients. The use of surface electromyography in assessing muscle fatigue is an excellent diagnostic tool for identifying patients with temporomandibular dysfunction.

Influence of intramuscular granisetron on experimentally induced muscle pain by acidic saline.

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Louca, S; Ernberg, M; Christidis, N

2013-06-01

The aim of this study was to investigate whether intramuscular administration of the 5-HT(3) receptor antagonist granisetron reduces experimental muscle pain induced by repeated intramuscular injections of acidic saline into the masseter muscles. Twenty-eight healthy and pain-free volunteers, fourteen women and fourteen men participated in this randomized, double-blind and placebo-controlled study. After a screening examination and registration of the baseline pressure-pain threshold (PPT), the first simultaneous bilateral injections of 0·5 mL acidic saline (9 mg mL(-1) , pH 3·3) into the masseter muscles were performed. Two days later, PPT and pain (VAS) were re-assessed. The masseter muscle was then pre-treated with 0·5 mL granisetron (Kytril(®) 1 mg mL(-1) pH 5·3) on one side and control substance (isotonic saline, 9 mg mL(-1) pH 6) on the contralateral side. Two minutes thereafter a bilateral simultaneous injection of 0·5 mL acidic saline followed. The evoked pain intensity, pain duration, pain area and PPT were assessed. The volunteers returned 1 week later to re-assess VAS and PPT. On the side pre-treated with granisetron, the induced pain had significantly lower intensity and shorter duration (P granisetron on pain duration was significant only in women (P granisetron has a pain-reducing effect on experimentally induced muscle pain by repeated acidic saline injection. © 2013 John Wiley & Sons Ltd.

Protective Effects of Clenbuterol against Dexamethasone-Induced Masseter Muscle Atrophy and Myosin Heavy Chain Transition.

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Daisuke Umeki

Full Text Available Glucocorticoid has a direct catabolic effect on skeletal muscle, leading to muscle atrophy, but no effective pharmacotherapy is available. We reported that clenbuterol (CB induced masseter muscle hypertrophy and slow-to-fast myosin heavy chain (MHC isoform transition through direct muscle β2-adrenergic receptor stimulation. Thus, we hypothesized that CB would antagonize glucocorticoid (dexamethasone; DEX-induced muscle atrophy and fast-to-slow MHC isoform transition.We examined the effect of CB on DEX-induced masseter muscle atrophy by measuring masseter muscle weight, fiber diameter, cross-sectional area, and myosin heavy chain (MHC composition. To elucidate the mechanisms involved, we used immunoblotting to study the effects of CB on muscle hypertrophic signaling (insulin growth factor 1 (IGF1 expression, Akt/mammalian target of rapamycin (mTOR pathway, and calcineurin pathway and atrophic signaling (Akt/Forkhead box-O (FOXO pathway and myostatin expression in masseter muscle of rats treated with DEX and/or CB.Masseter muscle weight in the DEX-treated group was significantly lower than that in the Control group, as expected, but co-treatment with CB suppressed the DEX-induced masseter muscle atrophy, concomitantly with inhibition of fast-to-slow MHC isoforms transition. Activation of the Akt/mTOR pathway in masseter muscle of the DEX-treated group was significantly inhibited compared to that of the Control group, and CB suppressed this inhibition. DEX also suppressed expression of IGF1 (positive regulator of muscle growth, and CB attenuated this inhibition. Myostatin protein expression was unchanged. CB had no effect on activation of the Akt/FOXO pathway. These results indicate that CB antagonizes DEX-induced muscle atrophy and fast-to-slow MHC isoform transition via modulation of Akt/mTOR activity and IGF1 expression. CB might be a useful pharmacological agent for treatment of glucocorticoid-induced muscle atrophy.

Central representation of muscle pain and mechanical hyperesthesia in the orofacial region: a positron emission tomography study

DEFF Research Database (Denmark)

Kupers, Rron; Svensson, Peter; Jensen, Troels Staehlin

2004-01-01

Functional neuroimaging studies of the human brain have revealed a network of brain regions involved in the processing of nociceptive information. However, little is known of the cerebral processing of pain originating from muscles. The aim of this study was to investigate the cerebral activation...... pattern evoked by experimental jaw-muscle pain and its interference by simultaneous mechanical stimuli, which has been shown to evoke hyperesthesia. Ten healthy subjects participated in a PET study and jaw-muscle pain was induced by bolus injections of 5% hypertonic saline into the right masseter muscle....... Repeated von Frey hair stimulation (0.5 Hz) of the skin above the masseter muscle was used as the mechanical stimulus. Hypertonic saline injections caused strong muscle pain spreading to adjacent areas. von Frey stimulation was rated as non-painful but produced hyperesthesia during jaw-muscle pain. Jaw...

Myosin heavy chain expression in rabbit masseter muscle during postnatal development

NARCIS (Netherlands)

Bredman, J. J.; Weijs, W. A.; Korfage, H. A.; Brugman, P.; Moorman, A. F.

1992-01-01

The expression of isoforms of myosin heavy chain (MHC) during postnatal development was studied in the masseter muscle of the rabbit. Evidence is presented that in addition to adult fast and slow myosin, the rabbit masseter contains neonatal and 'cardiac' alpha-MHC. During postnatal growth myosin

Inhibition of swallowing reflex following phosphorylation of extracellular signal-regulated kinase in nucleus tractus solitarii neurons in rats with masseter muscle nociception.

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Tsujimura, Takanori; Kitagawa, Junichi; Ueda, Koichiro; Iwata, Koichi

2009-02-06

Pain is associated with swallowing abnormalities in dysphagic patients. Understanding neuronal mechanisms underlying the swallowing abnormalities associated with orofacial abnormal pain is crucial for developing new methods to treat dysphagic patients. However, how the orofacial abnormal pain is involved in the swallowing abnormalities is not known. In order to evaluate neuronal mechanisms of modulation of the swallows by masticatory muscle pain, here we first induced swallows by topical administration of distilled water to the pharyngolaryngeal region. The swallowing reflex was significantly inhibited after capsaicin (10, 30mM) injection into the masseter muscle compared to vehicle injection. Moreover the number of phosphorylated extracellular signal-regulated kinase-like immunoreactive (pERK-LI) neurons in the nucleus tractus solitarii (NTS) was significantly increased in the rats with capsaicin injection into the masseter muscle compared to that with vehicle injection. Rostro-caudal distribution of pERK-LI neurons in the NTS was peaked at the obex level. The capsaicin-induced inhibitory effect on swallowing reflex was reversed after intrathecal administration of mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor, PD98059. The present findings suggest that phosphorylation of ERK in NTS neurons may be involved in capsaicin-induced inhibition of swallowing reflex.

Three-dimensional CT might be a potential evaluation modality in correction of asymmetrical masseter muscle hypertrophy by botulinum toxin injection.

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No, Yeon A; Ahn, Byeong Heon; Kim, Beom Joon; Kim, Myeung Nam; Hong, Chang Kwon

2016-01-01

For correction of this asymmetrical hypertrophy, botulinum toxin type A (BTxA) injection is one of convenient treatment modalities. Unfortunately, physical examination of masseter muscle is not enough to estimate the exact volume of muscle hypertrophy difference. Two Koreans, male and female, of bilateral masseter hypertrophy with asymmetricity were evaluated. BTxA (NABOTA(®), Daewoong, Co. Ltd., Seoul, Korea) was injected at master muscle site with total 50 U (25 U at each side) and volume change was evaluated with three-dimensional (3D) CT image analysis. Maximum reduction of masseter hypertrophy was recognized at 2-month follow-up and reduced muscle size started to restore after 3 months. Mean reduction of masseter muscle volume was 36% compared with baseline. More hypertrophied side of masseter muscle presented 42% of volume reduction at 2-month follow-up but less hypertrophied side of masseter muscle showed 30% of volume shrinkage. In conclusion, 3D CT image analysis might be the exact evaluation tool for correction of asymmetrical masseter hypertrophy by botulinum toxin injection.

Jaw-motor effects of experimental jaw-muscle pain and stress in patients with deep bite and matched control subjects

DEFF Research Database (Denmark)

Sonnesen, Liselotte; Svensson, Peter

2013-01-01

clenching, during evoked pain and stress between deep bite patients and controls was investigated. DESIGN: In 30 deep bite patients and in 30 sex-/age-matched controls with neutral occlusion EMG activity was recorded bilaterally from masseter and anterior temporalis muscles before and during evoked pain......OBJECTIVE: The effect of experimental jaw-muscle pain and stress on masticatory muscle activity in TMD-patients has been discussed. Furthermore, associations between TMD and deep bite patients have been studied. Accordingly in the present study, comparison of EMG responses at rest, maximal...... and before and during a stress task. Evoked pain was induced by injections of glutamate into the masseter (local pain) and brachioradialis (remote pain) muscles and resting EMG activity was recorded before and after 1, 2, 3, 4, 5 and 10min. A precision task was used to simulate a stressful condition and EMG...

Functional compartmentalization of the human superficial masseter muscle.

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Rodrigo A Guzmán-Venegas

Full Text Available Some muscles have demonstrated a differential recruitment of their motor units in relation to their location and the nature of the motor task performed; this involves functional compartmentalization. There is little evidence that demonstrates the presence of a compartmentalization of the superficial masseter muscle during biting. The aim of this study was to describe the topographic distribution of the activity of the superficial masseter (SM muscle's motor units using high-density surface electromyography (EMGs at different bite force levels. Twenty healthy natural dentate participants (men: 4; women: 16; age 20±2 years; mass: 60±12 kg, height: 163±7 cm were selected from 316 volunteers and included in this study. Using a gnathodynamometer, bites from 20 to 100% maximum voluntary bite force (MVBF were randomly requested. Using a two-dimensional grid (four columns, six electrodes located on the dominant SM, EMGs in the anterior, middle-anterior, middle-posterior and posterior portions were simultaneously recorded. In bite ranges from 20 to 60% MVBF, the EMG activity was higher in the anterior than in the posterior portion (p-value = 0.001.The center of mass of the EMG activity was displaced towards the posterior part when bite force increased (p-value = 0.001. The topographic distribution of EMGs was more homogeneous at high levels of MVBF (p-value = 0.001. The results of this study show that the superficial masseter is organized into three functional compartments: an anterior, a middle and a posterior compartment. However, this compartmentalization is only seen at low levels of bite force (20-60% MVBF.

Metabolic changes of masseter muscle in experimental unilateral bite-raised rat determined by 31P-MRS

International Nuclear Information System (INIS)

Nishide, Naoto

1997-01-01

Occlusal interference is known to alter the functional activity of masticatory muscle, but no alteration of the energy metabolism of masticatory muscle which has gone occlusal interference has been reported. The purpose of this study was to investigate the energy metabolism in rat masseter muscle during masticatory movements following unilateral bite-raising. A bite-raising splint (1 mm) was fixed on the unilateral upper molar of experimental rats, and after 2, 4 and 6 weeks, the rats were anesthetized and masticatory movements were induced by electrical stimulation applied to the masseter muscle (with a biting force of 40 g, a frequency of 5 Hz and a stimulation time of 32 min). 31 P Magnetic Resonance Spectroscopy of the masseter muscle were recorded during a sequence of rest, stimulation and recovery periods, and the resonance signal area ratio of PCr and Pi ((PCr)/(PCr + Pi)) and the muscle pH were determined. After 4 and 6 weeks following the bite-raising, the masseter of the bite-raised side showed a decrease in the (PCr)/(PCr + Pi) ratio compared with a control group during stimulation (p<0.05). Neither the bite-raised side masseter at 2 weeks and the contralateral side at 4 weeks showed any differences compared with the control. The muscle pH during stimulation was similar in both the control and the bite-raised groups of rats. These findings suggest that the occlusal alteration induced by unilateral bite-raising reduces the masseter energy level during mastication. (author)

Experimental muscle pain produces central modulation of proprioceptive signals arising from jaw muscle spindles.

Science.gov (United States)

Capra, N F; Ro, J Y

2000-05-01

The aim of the present study was to investigate the effects of intramuscular injection with hypertonic saline, a well-established experimental model for muscle pain, on central processing of proprioceptive input from jaw muscle spindle afferents. Fifty-seven cells were recorded from the medial edge of the subnucleus interpolaris (Vi) and the adjacent parvicellular reticular formation from 11 adult cats. These cells were characterized as central units receiving jaw muscle spindle input based on their responses to electrical stimulation of the masseter nerve, muscle palpation and jaw stretch. Forty-five cells, which were successfully tested with 5% hypertonic saline, were categorized as either dynamic-static (DS) (n=25) or static (S) (n=20) neurons based on their responses to different speeds and amplitudes of jaw movement. Seventy-six percent of the cells tested with an ipsilateral injection of hypertonic saline showed a significant modulation of mean firing rates (MFRs) during opening and/or holding phases. The most remarkable saline-induced change was a significant reduction of MFR during the hold phase in S units (100%, 18/18 modulated). Sixty-nine percent of the DS units (11/16 modulated) also showed significant changes in MFRs limited to the hold phase. However, in the DS neurons, the MFRs increased in seven units and decreased in four units. Finally, five DS neurons showed significant changes of MFRs during both opening and holding phases. Injections of isotonic saline into the ipsilateral masseter muscle had little effect, but hypertonic saline injections made into the contralateral masseter muscle produced similar results to ipsilateral injections with hypertonic saline. These results unequivocally demonstrate that intramuscular injection with an algesic substance, sufficient to produce muscle pain, produces significant changes in the proprioceptive properties of the jaw movement-related neurons. Potential mechanisms involved in saline-induced changes in the

Histochemical and functional fibre typing of the rabbit masseter muscle

NARCIS (Netherlands)

Bredman, J. J.; Weijs, W. A.; Moorman, A. F.; Brugman, P.

1990-01-01

The fibre-type distribution of the masseter muscle of the rabbit was studied by means of the myosin-ATPase and succinate dehydrogenase reactions. Six different fibre types were found and these were unequally distributed between and within the anatomical compartments of the muscle. Most of the

Macrophages and mast cells in dystrophic masseter muscle: a light and electron microscopic study

DEFF Research Database (Denmark)

Kirkeby, S; Mikkelsen, H

1988-01-01

Macrophages and mast cells in masseter muscle from normal and dystrophic mice were studied by light and electron microscopy. Acid phosphatase activity and FITC-dextran were used to identify and describe macrophages. Toluidine blue was used as a marker for mast cells. In dystrophic muscle, the num......Macrophages and mast cells in masseter muscle from normal and dystrophic mice were studied by light and electron microscopy. Acid phosphatase activity and FITC-dextran were used to identify and describe macrophages. Toluidine blue was used as a marker for mast cells. In dystrophic muscle...

MOTOR UNIT TERRITORIES AND FIBER TYPES IN RABBIT MASSETER MUSCLE

NARCIS (Netherlands)

WEIJS, WA; JUCH, PJW; KWA, SHS; KORFAGE, JAM

1993-01-01

The myosin heavy chain (MHC) content and spatial distribution of the fibers of 11 motor units (MUs) of the rabbit masseter muscle were determined. The fibers of single MUs were visualized in whole-muscle serial sections by a negative periodic acid/Schiff reaction for glycogen after they had been

Can palpation-induced muscle pain pattern contribute to the differential diagnosis among temporomandibular disorders, primary headaches phenotypes and possible bruxism?

Science.gov (United States)

Porporatti, André-Luís; Calderon, Patrícia-dos-Santos; Conti, Paulo-César-Rodrigues; Bonjardim, Leonardo-Rigoldi

2016-01-01

Background The evaluation of possible differences in the distribution or characteristics of palpation-induced pain in the masticatory muscles could be valuable in terms of diagnostic assessment. The aim of this study was to evaluate the impact of different combinations of anterior temporalis (AT) and masseter palpation-induced pain in the diagnostic of temporomandibular disorder (TMD), primary headaches and bruxism. Material and Methods A total of 1200 dental records of orofacial pain adult patients were analyzed. The outcomes were dichotomously classified (presence/absence) as following: a) AT and/or masseter palpation-induced pain; b) myogenous TMD; c) temporomandibular joint (TMJ) arthralgia (arthrogenous TMD); d) migraine; e) tension-type headache (TTH); f) self-reported bruxism. Binomial logistic regression model (α = 5%) was applied to the data considering the palpation-induced muscle pain as the dependent variable. Results Mean age (SD) were 35.7 years (13.4) for 635 included dental records (83% females). Myogenous and arthrogenous TMD, migraine, TTH and bruxism were mainly associated with, respectively, masseter palpation-induced pain (ppain (ppain (ppain (p=0.009 - OR=1.62, 95%CI 1.12-2.33) and bilateral masseter palpation-induced pain (p=0.01 - OR=1.74, 95%CI 1.13-2.69). Conclusions Palpation-induced pain in the masticatory muscles may play a role in the differential diagnosis among painful TMD, primary headaches and bruxism. Key words:Diagnosis, temporomandibular joint disorders, migraine, tension-type headache, bruxism. PMID:26615507

Can palpation-induced muscle pain pattern contribute to the differential diagnosis among temporomandibular disorders, primary headaches phenotypes and possible bruxism?

Science.gov (United States)

Costa, Yuri-Martins; Porporatti, André-Luís; Calderon, Patrícia-dos-Santos; Conti, Paulo-César-Rodrigues; Bonjardim, Leonardo-Rigoldi

2016-01-01

The evaluation of possible differences in the distribution or characteristics of palpation-induced pain in the masticatory muscles could be valuable in terms of diagnostic assessment. The aim of this study was to evaluate the impact of different combinations of anterior temporalis (AT) and masseter palpation-induced pain in the diagnostic of temporomandibular disorder (TMD), primary headaches and bruxism. A total of 1200 dental records of orofacial pain adult patients were analyzed. The outcomes were dichotomously classified (presence/absence) as following: a) AT and/or masseter palpation-induced pain; b) myogenous TMD; c) temporomandibular joint (TMJ) arthralgia (arthrogenous TMD); d) migraine; e) tension-type headache (TTH); f) self-reported bruxism. Binomial logistic regression model (α = 5%) was applied to the data considering the palpation-induced muscle pain as the dependent variable. Mean age (SD) were 35.7 years (13.4) for 635 included dental records (83% females). Myogenous and arthrogenous TMD, migraine, TTH and bruxism were mainly associated with, respectively, masseter palpation-induced pain (pbruxism.

Schedule-induced masseter EMG in facial pain subjects vs. no-pain controls.

Science.gov (United States)

Gramling, S E; Grayson, R L; Sullivan, T N; Schwartz, S

1997-02-01

Empirical reports suggest that oral habits (e.g., teeth clenching) may be behavioral mediators linking stress to muscle hyperreactivity and the development of facial pain. Another report suggests that excessive behavioral adjuncts develop in conjunction with fixed-time stimulus presentation. The present study assessed the extent to which the oral habits exhibited by facial pain patients are schedule-induced. Subjects with Temporomandibular Disorder (TMD) symptomatology (n = 15) and pain-free controls (n = 15) participated in a 4-phase experiment (adaptation, baseline, task, recovery) designed to elicit schedule-induced behaviors. Self-report of oral habits and negative affect were recorded after each phase. Objective measures of oral habits were obtained via behavioral observation and masseter EMG recordings. Results revealed that negative arousal significantly increased during the fixed-time (FT) task and was also associated with increased oral habits among the TMD subjects. Moreover, 40% of the TMD subjects and none of the controls exhibited a pattern of EMG elevations in the early part of the inter-stimulus interval that met a strict criteria for scheduled-induced behavior per se. Taken together, these results suggest that the TMD subjects were engaging in schedule-induced oral habits. The adjunctive behavior literature seems to provide a plausible explanation as to how oral habits develop and are maintained in TMD patients, despite their painful consequences.

Metabolic changes of masseter muscle in experimental unilateral bite-raised rat determined by {sup 31}P-MRS

Energy Technology Data Exchange (ETDEWEB)

Nishide, Naoto [Kyoto Prefectural Univ. of Medicine (Japan)

1997-05-01

Occlusal interference is known to alter the functional activity of masticatory muscle, but no alteration of the energy metabolism of masticatory muscle which has gone occlusal interference has been reported. The purpose of this study was to investigate the energy metabolism in rat masseter muscle during masticatory movements following unilateral bite-raising. A bite-raising splint (1 mm) was fixed on the unilateral upper molar of experimental rats, and after 2, 4 and 6 weeks, the rats were anesthetized and masticatory movements were induced by electrical stimulation applied to the masseter muscle (with a biting force of 40 g, a frequency of 5 Hz and a stimulation time of 32 min). {sup 31}P Magnetic Resonance Spectroscopy of the masseter muscle were recorded during a sequence of rest, stimulation and recovery periods, and the resonance signal area ratio of PCr and Pi ((PCr)/(PCr + Pi)) and the muscle pH were determined. After 4 and 6 weeks following the bite-raising, the masseter of the bite-raised side showed a decrease in the (PCr)/(PCr + Pi) ratio compared with a control group during stimulation (p<0.05). Neither the bite-raised side masseter at 2 weeks and the contralateral side at 4 weeks showed any differences compared with the control. The muscle pH during stimulation was similar in both the control and the bite-raised groups of rats. These findings suggest that the occlusal alteration induced by unilateral bite-raising reduces the masseter energy level during mastication. (author)

The capillary pattern in human masseter muscle during ageing

Czech Academy of Sciences Publication Activity Database

Cvetko, E.; Janáček, Jiří; Kubínová, Lucie; Eržen, I.

2013-01-01

Roč. 32, č. 3 (2013), s. 135-144 ISSN 1580-3139 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : 3D analysis * capillaries * confocal microscopy * human * masseter * muscle Subject RIV: EA - Cell Biology Impact factor: 0.697, year: 2013

A intervenção fonoaudiológica no pós-operatório da hipertrofia benigna do músculo masseter The miofunctional oral intervention in the surgery treatment for the masseter muscle hipertrophy

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Laura Davison Mangilli

2006-04-01

Full Text Available OBJETIVO: descrever a abordagem fonoaudiológica no pós-operatório de pacientes que realizaram correção cirúrgica da hipertrofia do músculo masseter. METODOLOGIA: foram coletados dados referentes à avaliação e ao tratamento fonoaudiológico de 4 prontuários de sujeitos de ambos os gêneros, com faixa etária entre 16 e 24 anos, com hipertrofia benigna do músculo masseter, tratados cirurgicamente. RESULTADOS: as principais queixas pós-cirúrgicas estiveram relacionadas à limitação da abertura da boca, à dor na região da cirurgia, à rigidez muscular e a estalo em região da ATM. A terapia fonoaudiológica baseou-se em orientação quanto à retirada de hábitos deletérios; termoterapia na região do músculo masseter; manipulação da musculatura envolvida extra e intrabucais; alongamento da musculatura facial e cervical; alavanca de abertura forçada de boca e exercícios de órgãos fonoarticulatórios. CONCLUSÕES: a terapia fonoaudiológica apresenta-se como uma possibilidade de complementação ao tratamento cirúrgico, na adequação da amplitude dos movimentos mandibulares, assim como na eliminação dos sintomas presentes no pós-cirúrgico e na conscientização dos hábitos deletérios, que são apontados pela literatura como possíveis fatores desencadeantes.AIM: the aim of this study was to describe miofunctional oral intervention in patients with Masseter muscle hipertrophy treated by surgery. METHODS: the sample consisted of 4 patients, male and female, with ages between 16 and 24 years, with Masseter muscle hipertrophy treated by surgery. RESULTS: the main complains on the postoperative were related to trismus, muscle rigidity, and clicking in the temporomandibular joint. The myofunctional oral therapy was based on orientation in the abnormal habits (bruxism, clenching elimination, hyperthermia induced in the masseter muscle, oral muscles massage, facial and cervical muscles stretching, miofunctional exercises and

Asymmetric activation of temporalis, masseter, and sternocleidomastoid muscles in temporomandibular disorder patients.

Science.gov (United States)

Ries, Lilian Gerdi Kittel; Alves, Marcelo Correa; Bérzin, Fausto

2008-01-01

The aim of this study was to analyze the symmetry of the electromyographic (EMG) activity of the temporalis, masseter, and sternocleidomastoid (SCM) muscles in volunteers divided into a control group and a temporomandibular disorder (TMD) group. The surface EMG recordings were made during mandibular rest position, maximal intercuspal position, and during the chewing cycle. Normalized EMG waves of paired muscles were compared by computing a percentage overlapping coefficient (POC). The difference between the groups and between the static and dynamic clenching tests was analyzed through repeated measures, ANOVA. Symmetry of the temporalis, masseter, and SCM muscles activity was smaller in the TMD group compared to the control group. The mandibular postures were also significantly different among themselves. The asymmetric activation of jaw and neck muscles was interpreted as a compensatory strategy to achieve stability for the mandibular and cervical systems during masticatory function.

Recurrent parotid swelling secondary to masseter muscle hypertrophy: a multidisciplinary diagnostic and therapeutic approach.

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Capaccio, Pasquale; Gaffuri, Michele; Pignataro, Lorenzo; Assandri, Fausto; Pereira, Pollyanna; Farronato, Giampietro

2016-11-01

To present a patient with an atypical recurrent parotid swelling due to masseter muscle hypertrophy and the diagnostic/therapeutic assessment to treat this condition. A patient referring recurrent right facial swelling underwent a complete multidisciplinary assessment of the parotid region that revealed masseter muscle hypertrophy, confirmed by means of clinical (otolaryngological and gnathological evaluation), radiological (utrasonography, dynamic magnetic resonance imaging, and cone beam computed tomography), instrumental (electromyography to evaluate the right masseter muscle function and kinesiography to evaluate maximum right deflection - MaxRDefl and maximum opening - MaxMO) and sialendoscopy assessment where T0 indicates the pre-treatment values. All electromyographic and kinesiographic parameters were evaluated six months after the orthodontic application of a neuromuscular orthosis at T1. At T1, the effectiveness of the orthodontic therapy was demonstrated by the complete resolution of symptoms, and instrumental results documented more efficient muscle activity at rest and during clenching and a better mandibular position. At EMG T1, the resting and post-TENS values were, respectively, 1.2 and 1.8 microV. At kinesiography, MaxRDefl increased from 10.2 (T0) to 10.5 mm (T1); maxMO increased from 41.2 (T0) to 48 mm (T1). The proposed multidisciplinary assessment based on otolaryngological, gnathological, and radiological evaluation may be useful in the case of recurrent parotid swelling secondary to masseter muscle hypertrophy to plan an appropriate management with a removable neuromuscular orthosis.

Fibrodysplasia ossificans circumscripta of the masseter muscle.

Science.gov (United States)

Geist, J R; Bhatti, P; Plezia, R A; Wesley, R K

1998-05-01

Fibrodysplasia ossificans circumscripta (FOC) is a lesion characterized by localized calcification of the investing fascia of skeletal muscle. It is often related to repeated trauma and was formerly known as traumatic myositis ossificans. Surgical procedures involving muscles are also believed to be a factor in the origin of the lesion. When FOC develops in the muscles of mastication it can lead to severe trismus. A case is reported of FOC in the left masseter muscle of a 44-year-old man who presented with marked limitation of opening. It was believed that previous fractures of the left maxilla and mandible and/or the subsequent surgical treatments were responsible for the onset of FOC. The radiographic and microscopic features of FOC are discussed in relation to recent theories on the etiology, pathogenesis, and treatment of the lesion.

Immediate effects of hamstring stretching alone or combined with ischemic compression of the masseter muscle on hamstrings extensibility, active mouth opening and pain in athletes with temporomandibular dysfunction.

Science.gov (United States)

Espejo-Antúnez, Luis; Castro-Valenzuela, Elisa; Ribeiro, Fernando; Albornoz-Cabello, Manuel; Silva, Anabela; Rodríguez-Mansilla, Juan

2016-07-01

To assess the immediate effects of hamstrings stretching alone or combined with ischemic compression of the masseter muscle on hamstrings extensibility, active mouth opening and pain in athletes with temporomandibular dysfunction and hamstrings shortening. Forty-two participants were randomized to receive the stretching technique (n = 21) or the stretching plus the ischemic compression (n = 21). Outcome measures were: hamstrings extensibility, active mouth opening, pressure pain thresholds and pain intensity. Both interventions improved significantly active mouth opening (group 1: 35.7 ± 6.7 to 39.1 ± 7.6 mm, p Hamstrings stretching induced an acute improvement in hamstrings extensibility, active mouth opening and pain. Moreover, the addition of ischemic compression did not induce further improvements on the assessed parameters. Copyright © 2016. Published by Elsevier Ltd.

Peripheral Receptor Mechanisms Underlying Orofacial Muscle Pain and Hyperalgesia

Science.gov (United States)

Saloman, Jami L.

Musculoskeletal pain conditions, particularly those associated with temporomandibular joint and muscle disorders (TMD) are severely debilitating and affect approximately 12% of the population. Identifying peripheral nociceptive mechanisms underlying mechanical hyperalgesia, a prominent feature of persistent muscle pain, could contribute to the development of new treatment strategies for the management of TMD and other muscle pain conditions. This study provides evidence of functional interactions between ligand-gated channels, P2X3 and TRPV1/TRPA1, in trigeminal sensory neurons, and proposes that these interactions underlie the development of mechanical hyperalgesia. In the masseter muscle, direct P2X3 activation, via the selective agonist αβmeATP, induced a dose- and time-dependent hyperalgesia. Importantly, the αβmeATP-induced hyperalgesia was prevented by pretreatment of the muscle with a TRPV1 antagonist, AMG9810, or the TRPA1 antagonist, AP18. P2X3 was co-expressed with both TRPV1 and TRPA1 in masseter muscle afferents confirming the possibility for intracellular interactions. Moreover, in a subpopulation of P2X3 /TRPV1 positive neurons, capsaicin-induced Ca2+ transients were significantly potentiated following P2X3 activation. Inhibition of Ca2+-dependent kinases, PKC and CaMKII, prevented P2X3-mechanical hyperalgesia whereas blockade of Ca2+-independent PKA did not. Finally, activation of P2X3 induced phosphorylation of serine, but not threonine, residues in TRPV1 in trigeminal sensory neurons. Significant phosphorylation was observed at 15 minutes, the time point at which behavioral hyperalgesia was prominent. Similar data were obtained regarding another nonselective cation channel, the NMDA receptor (NMDAR). Our data propose P2X3 and NMDARs interact with TRPV1 in a facilitatory manner, which could contribute to the peripheral sensitization underlying masseter hyperalgesia. This study offers novel mechanisms by which individual pro-nociceptive ligand

The pedicled masseter muscle transfer for smile reconstruction in facial paralysis: repositioning the origin and insertion.

Science.gov (United States)

Matic, Damir B; Yoo, John

2012-08-01

The pedicled masseter muscle transfer (PMMT) is introduced as a new reconstructive option for dynamic smile restoration in patients with facial paralysis. The masseter muscle is detached from both its origin and insertion and transferred to a new position to imitate the function of the native zygomaticus major muscle. Part one of this study consisted of cadaveric dissections of 4 heads (eight sides) in order to determine whether the masseter muscle could be (a) pedicled solely by its dominant neurovascular bundle and (b) repositioned directly over the native zygomaticus major. The second part of the study consisted of clinical assessments in three patients in order to confirm the applicability of this muscle transfer. Commissure excursion and vector of contraction following PMMT were compared to the non-paralyzed side. In all eight sides, the masseter muscles were successfully isolated on their pedicle and transposed on top of and in-line with the ipsilateral zygomaticus major. The mean length of the masseter and its angle from Frankfurt's horizontal line after transposition compared favorably to the native zygomaticus major muscle. In the clinical cases, the mean commissure movements of the paralyzed and normal sides were 7 mm and 12 mm respectively. The mean angles of commissural movement for the paralyzed and normal sides were 62° and 59° respectively. The PMMT can be used as a dynamic reconstruction for patients with permanent facial paralysis. As we gain experience with the PMMT, it may be possible to use it as a first-line option for patients not eligible for free micro-neurovascular reconstruction. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Tumor Necrosis Factor Alpha Signaling in Trigeminal Ganglion Contributes to Mechanical Hypersensitivity in Masseter Muscle During Temporomandibular Joint Inflammation.

Science.gov (United States)

Ito, Reio; Shinoda, Masamichi; Honda, Kuniya; Urata, Kentaro; Lee, Jun; Maruno, Mitsuru; Soma, Kumi; Okada, Shinji; Gionhaku, Nobuhito; Iwata, Koichi

To determine the involvement of tumor necrosis factor alpha (TNFα) signaling in the trigeminal ganglion (TG) in the mechanical hypersensitivity of the masseter muscle during temporomandibular joint (TMJ) inflammation. A total of 55 male Sprague-Dawley rats were used. Following injection of Complete Freund's Adjuvant into the TMJ, the mechanical sensitivities of the masseter muscle and the overlying facial skin were measured. Satellite glial cell (SGC) activation and TNFα expression in the TG were investigated immunohistochemically, and the effects of their inhibition on the mechanical hypersensitivity of the masseter muscle were also examined. Student t test or two-way repeated-measures analysis of variance followed by Bonferroni multiple comparisons test were used for statistical analyses. P < .05 was considered to reflect statistical significance. Mechanical allodynia in the masseter muscle was induced without any inflammatory cell infiltration in the muscle after TMJ inflammation. SGC activation and an increased number of TNFα-immunoreactive cells were induced in the TG following TMJ inflammation. Intra-TG administration of an inhibitor of SGC activity or of TNFα-neutralizing antibody depressed both the increased number of TG cells encircled by activated SGCs and the mechanical hypersensitivity of the masseter following TMJ inflammation. These findings suggest that persistent masseter hypersensitivity associated with TMJ inflammation was mediated by SGC-TG neuron interactions via TNFα signaling in the TG.

Anatomic MRI study of a small muscle: the masseter

International Nuclear Information System (INIS)

Dheyriat, A.; Lissac, M.; Sappey-Marinier, D.; Bonmartin, A.

1997-01-01

Magnetic resonance imaging (MRI) provides functional information in an anatomic presentation allowing to distinguish soft tissues with high sensitivity. The goal of this study was to investigate the normal anatomy of the major masticatory muscle, the masseter, both at rest or during contraction by using three dimensional (3D) MRI. Eighteen subjects aged from 19 to 28 years, all in good health, were studied. Several experiments were first realized on phantoms to test the 3D-MRI technique. After reconstruction and segmentation processing, 3D acquisition, enabled obtaining data on the masseter anatomy. The normal anatomical position of the masseter was reported to the skin plan as the mean internal distance (7.9±0.42 mm) and external distance (15.2±0.41 mm). While there was no difference between internal distance, for sex or side, the external distance was significantly (p = 0.02) shorter in male (7.7±0.5 mm) than in female (8.8±0.4 mm) for both sides. The mean volume for all subjects and both sides (20.3±1.1 cm 3 ) did not change significantly between rest and exercise. The masseter volume was significantly (p 3 ) than in female (16.4±3.6 cm 3 ) groups. These physiological references may be useful for further MRI investigations of masticatory system pathologies. (authors)

Does pain in the masseter and anterior temporal muscles influence maximal bite force?

Science.gov (United States)

Goiato, Marcelo Coelho; Zuim, Paulo Renato Junqueira; Moreno, Amália; Dos Santos, Daniela Micheline; da Silva, Emily Vivianne Freitas; de Caxias, Fernanda Pereira; Turcio, Karina Helga Leal

2017-11-01

The aim of this study was to evaluate changes in pain and muscle force, and the relationship between them, in patients with muscle pain and bruxism, prior to and after treatment. Thirty women with bruxism and myofascial pain (Ia) were included in this study. Sleep bruxism diagnosis was made based on clinical diagnostic criteria, and awake bruxism diagnosis was made by patient questionnaires and the presence of tooth wear. The diagnosis of myofascial pain was established according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC-TMD). Dentulous or partially edentulous patients (rehabilitated with conventional fixed prostheses) were included in the study according to the inclusion and exclusion criteria. The pain treatment protocol included occlusal splints, patient education, and physiotherapy for 30days. Bite force was measured using a dynamometer at the central incisor and the first molar regions on both sides. The exams were performed at baseline, after 7days, and 30days after treatment. The Wilcoxon test was used to compare patient pain level response among the periods analyzed in the study. Bite force data were submitted to two-way repeated-measures ANOVA, followed by the Tukey HSD test (pforce. Results revealed that there was a statistical difference in pain level over time for both muscles and sides (pforce exhibited significantly higher values after 30days of treatment, when compared with the baseline (pforce only for the temporal muscle in all periods analyzed (pforce. Pain level decreased and bite force increased in the molar region after treatment. No strong correlation or dispersion in the relationship between pain levels and bite force was seen in women with myofascial pain and bruxism. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cervico-mandibular muscle activity in females with chronic cervical pain

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T. Lang

2013-12-01

Full Text Available Pathophysiological mechanisms behind pain in chroniccervical musculoskeletal conditions (MSC in office workers remainunclear. Chronic cervical pain has established links with temporomandibular(TM disorders. Yet there is no current published evidence to reportwhether individuals with cervical dysfunction exhibit altered masseterand cervical extensor (CE muscle activity. Objective: To explore CE andmasseter surface electromyographic (sEMG activity and teeth clenchinghabits in females with chronic cervical dysfunction and no TM disorder.Design: Descriptive cross-sectional correlational study with singleblinding.Participants: University students and staff with or without chroniccervical pain and no TM involvement. Methods: Descriptive and paindata captured from Research Diagnostic Criteria for TM disorders, NeckDisability Index, Computer Usage, Brief Pain Inventory, and EuroQoL-5Dquestionnaires. Female participants allocated to a chronic cervical (n = 20 and a control group (n = 22. Investigator blindedto the study groups recorded sEMG of bilateral masseter and CE muscles (C4/5 level at rest and during light teeth clenching.Results: No differences in socio-demographic profile; or in masseter or CE sEMG activity at rest or during light clench betweengroups. The pain group had higher scores for pain, reported a daytime teeth clenching habit, and had worse scores for the healthrelatedquality of life (HRQoL sub-sections for pain, anxiety/depression, and lower scores for perceived health status. Conclusion:No relationship established between cervico-mandibular sEMG activity and reported disability in females with chronic cervicaldysfunction and no TM disorder. Association between biopsychosocial factors of teeth clenching and anxiety/depression highlightscomplex pathophysiological mechanisms in chronic recurrent cervical pain.

Masseter muscle myofibrillar protein synthesis and degradation in an experimental critical illness myopathy model.

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Hazem Akkad

Full Text Available Critical illness myopathy (CIM is a debilitating common consequence of modern intensive care, characterized by severe muscle wasting, weakness and a decreased myosin/actin (M/A ratio. Limb/trunk muscles are primarily affected by this myopathy while cranial nerve innervated muscles are spared or less affected, but the mechanisms underlying these muscle-specific differences remain unknown. In this time-resolved study, the cranial nerve innervated masseter muscle was studied in a unique experimental rat intensive care unit (ICU model, where animals were exposed to sedation, neuromuscular blockade (NMB, mechanical ventilation, and immobilization for durations varying between 6 h and 14d. Gel electrophoresis, immunoblotting, RT-PCR and morphological staining techniques were used to analyze M/A ratios, myofiber size, synthesis and degradation of myofibrillar proteins, and levels of heat shock proteins (HSPs. Results obtained in the masseter muscle were compared with previous observations in experimental and clinical studies of limb muscles. Significant muscle-specific differences were observed, i.e., in the masseter, the decline in M/A ratio and muscle fiber size was small and delayed. Furthermore, transcriptional regulation of myosin and actin synthesis was maintained, and Akt phosphorylation was only briefly reduced. In studied degradation pathways, only mRNA, but not protein levels of MuRF1, atrogin-1 and the autophagy marker LC3b were activated by the ICU condition. The matrix metalloproteinase MMP-2 was inhibited and protective HSPs were up-regulated early. These results confirm that the cranial nerve innervated masticatory muscles is less affected by the ICU-stress response than limb muscles, in accordance with clinical observation in ICU patients with CIM, supporting the model' credibility as a valid CIM model.

Masseter muscle tension, chewing ability, and selected parameters of physical fitness in elderly care home residents in Lodz, Poland

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Gaszynska E

2014-07-01

Full Text Available Ewelina Gaszynska,1 Malgorzata Godala,2 Franciszek Szatko,1 Tomasz Gaszynski3 1Department of Hygiene and Health Promotion, Medical University of Lodz, Poland; 2Department of Nutrition and Epidemiology, Medical University of Lodz, Poland; 3Department of Emergency Medicine and Disaster Medicine, Medical University of Lodz, Poland Background: Maintaining good physical fitness and oral function in old age is an important element of good quality of life. Disability-related impairment of oral function contributes to a deterioration of the diet of older people and to the reduction of their social activity.Objectives: Investigate the association between masseter muscle tension, dental status, and physical fitness parameters.Materials and methods: Two hundred fifty-nine elderly care home residents (97 men, 162 women; mean age, 75.3±8.9 years were involved in this cross-sectional study. Their chewing ability was evaluated by masseter muscle tension palpation, differences of masseter muscle thickness, self-reported chewing ability, number of present and functional teeth, and number of posterior tooth pairs. Masseter muscle thickness was measured by ultrasonography. To assess physical fitness, hand grip strength and the timed up-and-go test were performed. Nutritional status was assessed using body mass index and body cell mass index (BCMI, calculated on the basis of electrical bioimpedance measurements. Medical records were used to collect information on systemic diseases and the number of prescribed medications. Subjects were also evaluated for their ability to perform ten activities of daily living.Results: Ninety-seven percent of the subjects suffered from systemic diseases. The three most prevalent illnesses were cardiac/circulatory 64.5%, musculoskeletal 37.3%, and endocrine/metabolic/nutritional 29.3%. Of the participants, 1.5% were underweight and more than one third (34.4% were overweight. Malnutrition (BCMI below normal was found in almost

Effect of triiodothyronine on the maxilla and masseter muscles of the rat stomatognathic system

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M.V. Mariúba

2011-07-01

Full Text Available The maxilla and masseter muscles are components of the stomatognathic system involved in chewing, which is frequently affected by physical forces such as gravity, and by dental, orthodontic and orthopedic procedures. Thyroid hormones (TH are known to regulate the expression of genes that control bone mass and the oxidative properties of muscles; however, little is known about the effects of TH on the stomatognathic system. This study investigated this issue by evaluating: i osteoprotegerin (OPG and osteopontine (OPN mRNA expression in the maxilla and ii myoglobin (Mb mRNA and protein expression, as well as fiber composition of the masseter. Male Wistar rats (~250 g were divided into thyroidectomized (Tx and sham-operated (SO groups (N = 24/group treated with T3 or saline (0.9% for 15 days. Thyroidectomy increased OPG (~40% and OPN (~75% mRNA expression, while T3 treatment reduced OPG (~40% and OPN (~75% in Tx, and both (~50% in SO rats. Masseter Mb mRNA expression and fiber type composition remained unchanged, despite the induction of hypo- and hyperthyroidism. However, Mb content was decreased in Tx rats even after T3 treatment. Since OPG and OPN are key proteins involved in the osteoclastogenesis inhibition and bone mineralization, respectively, and that Mb functions as a muscle store of O2 allowing muscles to be more resistant to fatigue, the present data indicate that TH also interfere with maxilla remodeling and the oxidative properties of the masseter, influencing the function of the stomatognathic system, which may require attention during dental, orthodontic and orthopedic procedures in patients with thyroid diseases.

A morphological study of the masseter muscle using magnetic resonance imaging in patients with jaw deformities. Cases demonstrating mandibular deviation

International Nuclear Information System (INIS)

Higashi, Katsuhiko; Goto, Tazuko K.; Kanda, Shigenobu; Shiratsuchi, Yuji; Nakashima, Akihiko; Horinouchi, Yasufumi

2006-01-01

Numerous studies on the cross-sectional area of masticatory muscles, which are correlated to the facial shape, have been reported for normal subjects in previous articles. However to date, there have been no such studies on masseter muscles at jaw-closing and jaw-opening in patients with jaw deformities involving mandibular deviation. The MRI data sets of the masseter muscles at jaw-closing and jaw-opening in 14 female patients with mandibular deviation, who demonstrated a more than 3-mm deviation in the median line in the lower first incisors in comparison to the upper ones, were utilized. The cross-sectional areas from the origin to the insertion at jaw-closing and jaw-opening which were reconstructed perpendicular to the three-dimensional long axis of each masseter muscle, each maximum cross-sectional area (MCSA) and the ratio of the change in MCSA after jaw-opening were analyzed. As a result, a significant difference was observed between the MCSA at jaw-closing and jaw-opening on the same side. However, no difference in MCSA was seen between the deviated and non-deviated side of the mandible. The line chart patterns of the masseter muscles from the origin to the insertion could be classified into four types. Our results suggest that it is important to analyze cross-sectional areas of the masseter muscles in each subject while considering the three-dimensional axis of each muscle. (author)

Masseter muscle surface electromyography in college students with a high degree of anxiety and temporomandibular disorder

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Eduarda de Lima Amarante

Full Text Available ABSTRACT Objective: to compare the electrical activity of masseter muscles, bilaterally, according to the presence or absence of Temporomandibular Disorder (TMD in college students with a high degree of anxiety. Methods: the study was conducted with a randomized sample of 31 Speech Therapy students aged between 17 and 32 years; 61.3% (n = 19 were females and 38.7% (n = 12 were males. They were divided into two groups, Group 1 (G1, comprising 11 students with TMD, and Group 2 (G2, composed of 20 students without TMD. The college students answered the State-Trait Anxiety Inventory (STAI for anxiety investigation, and were evaluated by the protocol Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD for TMD diagnosis. The evaluation of muscular electrical activity took into account the records in the conditions of rest, Sustained Maximum Voluntary Activity (SMVA and habitual chewing (HC. The data were analyzed using the version 22 IBM Statistical Package for Social Sciences (SPSS software. The statistical analysis was performed using Student t test to compare means between groups, considering < 0,05 as the significant p-value. Results: college students, of both groups, presented high levels of anxiety traits. Significant statistical differences were observed on the percentage of electrical activity of right masseter muscle in chewing function, as well as muscle fibers recruitment during chewing, which were higher on the group without TMD. Conclusion: college students with TMD and a high degree of anxiety presented lower means of masseter muscle electromyografic activity during chewing, in most conditions assessed, as compared to volunteers without TMD, except for the left masseter muscle in rest and chewing.

Anatomical analysis of human masseter using MRI

International Nuclear Information System (INIS)

Kitahara, Masaki

1990-01-01

To quantitatively elucidate individual variation in human masseter muscle, the cross sectional area of this muscle was measured in situ with MRI apparatus. The results were analyzed against age, body build and laterality in habitual mastication by bivariate correlation analysis. Materials included 52 healthy volunteers (26 males, 26 females). Right and left masseter areas and total cross sectional area of the face were measured in the same horizontal plane, and directly displayed on the console of the MRI apparatus. The areas of masseter muscles were not correlated with age or body build, but were positively correlated with the total cross sectional area of the face in the same horizontal plane. Because the left masseters tended to be larger than right, a method for evaluation of the relative size of each side of the messeters was established. This analysis revealed that the corrected dominance of the masseter corresponded, with high probability, to the habitual laterality in mastication. (author)

Anatomical analysis of human masseter using MRI

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Kitahara, Masaki (Showa Univ., Tokyo (Japan). School of Medicine)

1990-10-01

To quantitatively elucidate individual variation in human masseter muscle, the cross sectional area of this muscle was measured in situ with MRI apparatus. The results were analyzed against age, body build and laterality in habitual mastication by bivariate correlation analysis. Materials included 52 healthy volunteers (26 males, 26 females). Right and left masseter areas and total cross sectional area of the face were measured in the same horizontal plane, and directly displayed on the console of the MRI apparatus. The areas of masseter muscles were not correlated with age or body build, but were positively correlated with the total cross sectional area of the face in the same horizontal plane. Because the left masseters tended to be larger than right, a method for evaluation of the relative size of each side of the messeters was established. This analysis revealed that the corrected dominance of the masseter corresponded, with high probability, to the habitual laterality in mastication. (author).

Effects of chronic Akt/mTOR inhibition by rapamycin on mechanical overload-induced hypertrophy and myosin heavy chain transition in masseter muscle.

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Umeki, Daisuke; Ohnuki, Yoshiki; Mototani, Yasumasa; Shiozawa, Kouichi; Fujita, Takayuki; Nakamura, Yoshiki; Saeki, Yasutake; Okumura, Satoshi

2013-01-01

To examine the effects of the Akt/mammalian target of rapamycin (mTOR) pathway on masseter muscle hypertrophy and myosin heavy chain (MHC) transition in response to mechanical overload, we analyzed the effects of bite-opening (BO) on the hypertrophy and MHC composition of masseter muscle of BO-rats treated or not treated with rapamycin (RAPA), a selective mTOR inhibitor. The masseter muscle weight in BO-rats was significantly greater than that in controls, and this increase was attenuated by RAPA treatment. Expression of slow-twitch MHC isoforms was significantly increased in BO-rats with/without RAPA treatment, compared with controls, but the magnitude of the increase was much smaller in RAPA-treated BO-rats. Phosphorylation of p44/42 MAPK (ERK1/2), which preserves fast-twitch MHC isoforms in skeletal muscle, was significantly decreased in BO-rats, but the decrease was abrogated by RAPA treatment. Calcineurin signaling is known to be important for masseter muscle hypertrophy and fast-to-slow MHC isoform transition, but expression of known calcineurin activity modulators was unaffected by RAPA treatment. Taken together, these results indicate that the Akt/mTOR pathway is involved in both development of masseter muscle hypertrophy and fast-to-slow MHC isoform transition in response to mechanical overload with inhibition of the ERK1/2 pathway and operates independently of the calcineurin pathway.

The analgesic effect of photobiomodulation therapy (830 nm on the masticatory muscles: a randomized, double-blind study

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Sabrina Araújo Pinho Costa

2017-12-01

Full Text Available Abstract: This study assesses the efficacy of photobiomodulation therapy (830 nm for myalgia treatment of masticatory muscles. Sixty patients with muscular myalgia were selected and randomly allocated into 2 groups (n=30: Group A comprised patients given a placebo (control, and Group B consisted of those undergoing photobiomodulation therapy (PBMT. PBMT and placebo were applied bilaterally to specific points on the masseter and temporal muscles. Referred pain elicited by palpation and maximum mouth opening were measured before (EV1 and after (EV2 the treatments. The data were analyzed using statistical tests, considering a significance level of 5%. No significant differences in range were observed for active or passive mouth opening (p ≥ 0.05. Comparing the final outcomes (EV1-EV2 of both treatments, statistical significance was verified for total pain in the right masseter muscle (p = 0.001 and total pain (p = 0.005. In EV2, significant differences in pain reported with palpation were found between Groups A and B for the following: left posterior temporal muscle (p = 0.025, left superior masseter muscle (p = 0.036, inferior masseter muscle (p = 0.021, total pain (left side (p = 0.009, total masseter muscle (left side (p = 0.014, total temporal (left side (p = 0.024, and total pain (p = 0.035. We concluded that PBMT (830 nm reduces pain in algic points, but does not influence the extent of mouth opening in patients with myalgia.

The analgesic effect of photobiomodulation therapy (830 nm) on the masticatory muscles: a randomized, double-blind study.

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Costa, Sabrina Araújo Pinho; Florezi, Giovanna Piacenza; Artes, Gisele Ebling; Costa, Jessica Ribeiro da; Gallo, Rosane Tronchin; Freitas, Patricia Moreira de; Witzel, Andrea Lusvarghi

2017-12-18

This study assesses the efficacy of photobiomodulation therapy (830 nm) for myalgia treatment of masticatory muscles. Sixty patients with muscular myalgia were selected and randomly allocated into 2 groups (n=30): Group A comprised patients given a placebo (control), and Group B consisted of those undergoing photobiomodulation therapy (PBMT). PBMT and placebo were applied bilaterally to specific points on the masseter and temporal muscles. Referred pain elicited by palpation and maximum mouth opening were measured before (EV1) and after (EV2) the treatments. The data were analyzed using statistical tests, considering a significance level of 5%. No significant differences in range were observed for active or passive mouth opening (p ≥ 0.05). Comparing the final outcomes (EV1-EV2) of both treatments, statistical significance was verified for total pain in the right masseter muscle (p = 0.001) and total pain (p = 0.005). In EV2, significant differences in pain reported with palpation were found between Groups A and B for the following: left posterior temporal muscle (p = 0.025), left superior masseter muscle (p = 0.036), inferior masseter muscle (p = 0.021), total pain (left side) (p = 0.009), total masseter muscle (left side) (p = 0.014), total temporal (left side) (p = 0.024), and total pain (p = 0.035). We concluded that PBMT (830 nm) reduces pain in algic points, but does not influence the extent of mouth opening in patients with myalgia.

[Trigeminal purinergic P2X4 receptor involved in experimental occlusal interference-induced hyperalgesia in rat masseter muscle].

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Xu, Xiaoxiang; Cao, Ye; Ding, Tingting; Fu, Kaiyuan; Xie, Qiufei

2016-03-01

To explore the expression of purinergic p2X4 receptor (P2X4R) in trigeminal ganglion of rats after occlusal interference. Investigation of peripheral receptor mechanism of occlusal interference-induced masticatory muscle pain will aid the development of drug intervention against this condition. Experimental occlusal interference was established by application of 0.4 mm metal crown to the upper right first molar of male Sprague-Dawley rats. Real-time PCR assay was used to investigate P2X4R mRNA level in trigeminal ganglion in rats with occlusal interference for 3, 7, 10 and 14 days and in control rats without occlusal interference (n=5 in each). Retrograde labelling combining immunofluorescence was performed to evaluate the percentage of P2X4R-positive cells in masseter afferent neurons (n=5 in each group). Graded concentrations of P2XR antagonist TNP-ATP (0.1, 10, 125, 250, 500 μmol/L) or saline (n=5 in each group) was administrated in right masseter and the mechanical sensitivity of bilateral masseters was measured before occlusal interference application, before the injection, and 30 min as well as 60 min after the injection. Compared with control rats (P2X4R mRNA: right side: 1.00±0.26, left side: 0.94± 0.21; percentage of P2X4R-positive masseter afferents: right side: [64.3±6.3]%, left side: [67.7±5.8]%), the level of P2X4R mRNA in bilateral trigeminal ganglia (right side: 5.98±3.56; left side: 5.06±2.88) of rats with occlusal interference for 7 days up-regulated (Pocclusal interference-induced masseter hyperalgesia.

Changes in the temporomandibular joint disc and temporal and masseter muscles secondary to bruxism in Turkish patients

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Hasan Garip

2018-01-01

Full Text Available Objectives: To analyze the relationships between temporalis and masseter muscle hypertrophy and temporomandibular joint (TMJ disc displacement in patients with severe bruxism using magnetic resonance imaging (MRI. Methods: This retrospective study included 100 patients with severe bruxism, referred to the Department of Oral and Maxillofacial Surgery, University of Marmara and Istanbul Medipol University, Istanbul, Turkey, between January 2015 and December 2016. Patients underwent TMJ MRI with a 1.5-T system in open and closed mouth positions. The masseter and temporalis muscles were measured in the axial plane when the patient’s mouth was closed. Results: At its thinnest, the disc averaged was 1.11±0.24 mm. At their thickest, the masseter averaged was 13.65±2.19 mm and temporalis muscles was 12.98±2.4 mm. Of the discs, 24% were positioned normally, 74% were positioned anteriorly, and 2% were positioned posteriorly. The temporalis muscle was significantly thicker in patients with normally positioned discs than in those with anteriorly positioned discs (p=0.035. Conclusions: The temporalis muscle was significantly thicker in patients with normally positioned discs than in those with anteriorly positioned discs (p=0.035. Additional studies should be conducted to evaluate the relationships between all masticatory and surrounding muscles and disc movements in patients with bruxism.

Electromyographic evaluation of masseter muscle activity in horses fed (i) different types of roughage and (ii) maize after different hay allocations.

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Vervuert, I; Brüssow, N; Bochnia, M; Cuddeford, D; Coenen, M

2013-06-01

The aims of this study were to monitor electromyographic (EMG) activity of masseter muscle in healthy horses fed (i) different types of roughage and (ii) maize after different hay allocations. Four horses were offered the following three diets ad libitum: hay, haylage or straw/alfalfa chaff (SAC). In a second trial, four horses were fed cracked maize (CM) and hay in three different orders: (i) CM after a 12-h overnight fast; (ii) CM immediately after restricted hay intake (0.6 kg hay/100 kg BW); or 3) CM after hay intake ad libitum. The activity of the masseter muscle was determined by EMG (IED(®) ), and the following were measured: amplitude (muscle action potential = MAP, maximum voltage) and duration of MAP (s). The intake of hay or haylage was associated with intense masseter muscle activity (MAP: hay, 10 ± 1.7 V; haylage, 11 ± 3.3 V; and duration of MAP: hay, 0.31 ± 0.04 s; haylage, 0.30 ± 0.04 s). Similar intense chewing was measured for SAC (MAP 13 ± 3.8 V), although duration of the chewing cycle was relatively short (0.22 ± 0.03 s, diet p haylage or SAC was associated with intensive masseter muscle activity that was likely to stimulate salivary flow rate. In contrast to roughage, concentrates like CM are consumed rapidly with less intensive masseter muscle activity. This situation is associated with a low salivary flow that may have an adverse effect on gastric function. © 2012 Blackwell Verlag GmbH.

Activity of masticatory muscles in subjects with different orofacial pain conditions.

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Bodéré, Céline; Téa, Say Hack; Giroux-Metges, Marie Agnes; Woda, Alain

2005-07-01

The existence of a pathophysiological link between tonic muscle activity and chronic muscle pain is still being debated. The purpose of this retrospective, controlled study was to evaluate the electromyographic (EMG) activity of masticatory muscles in subjects with different orofacial pain conditions. The temporal and masseter EMG activity at rest and the masseteric reflex were recorded in two groups of patients with either myofascial pain (n=33) or neuropathic pain (n=20), one group of non-pain patients with disc derangement disorders (n=27) and one control group of healthy, asymptomatic subjects (n=32). The EMG activities of both muscles at rest were significantly higher in the pain patient groups compared to the asymptomatic control group. There was no significant difference between the disc derangement disorder group and the control group. The masseteric reflex amplitude was reduced in all patient groups when compared with the control group. In pain patient groups, the increased EMG activity at rest and the reduction of the masseteric reflex amplitude were equally distributed in the pain and non-pain sides. In addition, subjects presenting with bilateral pain showed higher EMG activity at rest than those with unilateral pain. These results suggested that the modulation of muscle activity was not the direct consequence of a peripheral nociceptive mechanism and seemed to indicate that a central mechanism was at work. The contrast between the increased EMG activity at rest and the reduction of the masseteric reflex amplitude may reflect modulations of motoneurones that differed in tonic versus phasic conditions in chronic pain patients.

Masseter Muscle Hypertrophy and Pericardial Effusion in Kocher-Debre-Semelaigne Syndrome Child

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Taksande AM

2015-10-01

Full Text Available Muscular pseudohypertrophy associated with severe congenital hypothyroidism has been described as Kocher Debre Semelaigne syndrome, which is a rare disorder. We report a case of 9year old female child with hypothyroidism, limb muscular pseudo-hypertrophy with involvement of masseter muscle along with pericardial effusion in Kocher-Debré-Semelaigne syndrome.

The role in masseter muscle activities of functionally elicited periodontal afferents from abutment teeth under overdentures.

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Mushimoto, E

1981-09-01

Five overdenture wearers with a small number of remaining natural teeth were selected to evaluate the effect of the afferent input from periodontal mechanoreceptors on masseter activity in man. As a control, a full denture wearer was included. The subjects were instructed to chew a piece of gum, and/or tap their teeth. Surface EmG from the bilateral masseter muscles were recorded and analysed. When functional pressure was applied, during chewing, to the abutment teeth as well as to mucosa through the denture base, masseter activities were encouraged. Following application of anaesthesia to the periodontal membrane of the abutments, masseter activities were reduced. The duration of the silent period (SP) appearing in the EMG burst following tooth tapping was significantly increased with root support compared to mucosal support only. With topical anaesthesia of the periodontal tissues, SP duration decreased significantly. In conclusion, it has become apparent that the pressure sensibility of abutment teeth bearing functional pressure under an overdenture base is capable of facilitating masseter activity, as one of the sources of oral sensory input during mastication.

Effect of mini-implant-supported mandibular overdentures on electromyographic activity of the masseter muscle during chewing of hard and soft food.

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Ashmawy, Tarek Mohy; El Talawy, Dina Bahgat; Shaheen, Nasser Hussein

2014-09-01

To objectively evaluate the effect of mini-implant- supported mandibular overdentures on electromyographic activity (EMG) of the masseter muscle during chewing of hard and soft foods. Twelve completely edentulous patients (4 females and 8 males) with maladaptive experience of wearing mandibular dentures received new maxillary and mandibular dentures. After 3 months of adaptation, four mini dental implants (MDIs) were inserted in the interforaminal region of the mandible, and the new mandibular dentures were connected to the implants immediately with O/ring attachments. The activity of masseter muscle (EMG) and the duration of chewing cycle were measured during chewing hard (carrot) and soft (gum) foods. The measurements were made 3 months after wearing each of the following prostheses: the new conventional dentures; and the MDI-retained mandibular overdentures. The EMG of masseter muscle increased and the DC decreased with MDI-retained mandibular overdentures when compared to conventional dentures. Hard food (carrot) was associated with increased EMG and decreased DC when compared to soft food (gum) for both conventional dentures and MDI-retained mandibular overdentures. Mini-implant-supported mandibular overdentures are associated with increased activity of masseter muscle and decreased duration of chewing cycle for both hard and soft foods when compared to conventional dentures.

An electromyographic study on the sequential recruitment of bilateral sternocleidomastoid and masseter muscle activity during gum chewing.

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Guo, S-X; Li, B-Y; Zhang, Y; Zhou, L-J; Liu, L; Widmalm, S-E; Wang, M-Q

2017-08-01

Mandibular functions are associated with electromyographic activity of the jaw muscles and also the sternocleidomastoid muscle (SCM). The precise spatiotemporal relation of SCM and masticatory muscles activities during chewing is worthy of investigation. To analyse the sequential recruitment of SCM and masseter activities during chewing as indicated by the spatiotemporal locations of their activity peaks. Jaw movements and bilateral surface electromyographic activity of SCM and masseter were recorded during gum chewing in 20 healthy subjects. The timing order was decided by comparing the length of time from the time when the opening started to the time when the surface electromyographic activity reached its peak value. Spatial order was analysed by locating the peak electromyographic activity onto a standard chewing cycle which was created based on 15 unilateral chewing cycles. Paired t-test, one-way ANOVA and Student-Newman-Keuls post-test were used for comparisons. Although the Time to Peak for the balancing side SCM appeared shorter than for the other three tested muscles, most often it did not reach a level of significance. However, the location of the balancing side SCM's peak activity was further from the terminal chewing position (TCP) than the working side SCM and bilateral masseters (P < 0·05). The balancing side SCM activity reached its peak significantly further away from TCP than the other three tested muscles during chewing. Further studies with spatiotemporal variables included should be helpful to understand the roles of the head, neck and jaw muscles in orofacial and cervical dysfunctional problems. © 2017 John Wiley & Sons Ltd.

Clinical significance of isometric bite force versus electrical activity in temporal and masseter muscles

DEFF Research Database (Denmark)

Bakke, Merete; Michler, L; Han, K

1989-01-01

significant with respect to unilateral, but not to bilateral force measurements. Only in the masseter muscle was strength of dynamic contractions during chewing significantly correlated to bite force. With the present method it was demonstrated that unilateral bite force is a simple clinical indicator...

Congenital tri-cavernous hemangiomas of the right buccal region, right accessory parotid gland, and masseter muscle region.

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Yang, Tao; Gu, Yongchun; Zhang, Li; Hua, Zequan

2014-03-01

We report a rare case of congenital tri-cavernous hemangiomas of the right buccal region, right accessory parotid gland, and masseter muscle region in an adult. The patient, a 25-year-old woman, complained of 3 masses in her right midcheek. Ultrasonographic and computed tomographic findings showed an irregular-shaped mass (multiple calcifications) with a well-defined margin in the masseter muscle region, an ellipse-shaped mass (multiple calcifications) with a well-defined margin in the right buccal region, and a comma-shaped mass (no calcifications) with a well-defined margin separate from the parotid gland in the right accessory parotid gland region. These iconographic findings suggested that the masses were all hemangiomas separately originating from the parotid gland, accessory parotid gland, and masseter muscle. The masses were completely removed through a standard parotid incision without postoperative facial palsy, skin deformity, and difficulty in secreting saliva. Findings from histologic examination of the tumor revealed multiple, thin-walled, and dilated blood vessels, confirming the diagnosis of cavernous hemangiomas. Ultrasonographic and computed tomographic findings were extremely useful in diagnosing the mass/masses as hemangioma before surgery, clarifying relationships between the mass and adjacent structures, and determining the surgical approach to the mass/masses.

Initial Presentation of Renal Cell Carcinoma as a Metastatic Mass within the Masseter Muscle: A Case Report and Literature Review

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Bae, Kyung Eun; Lee, Han Bee; Cho, Woo Ho; Kim, Jae Hyung; Lee, Ji Hae; Kang, Min Jin [Dept. of Radiology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of); Kim, Hyun Jung [Dept. of Pathology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

2012-02-15

Renal cell carcinoma (RCC) is often concomitant with distant metastasis, and these metastases are the first sign of an otherwise occult primary. Whereas metastasis of RCC to the head and neck has been reported, metastasis to the masseter muscle, which is composed of skeletal muscle, is quite rare. We now report the case of a 66-year-old man who had a past history of pulmonary tuberculosis, with RCC metastasis of a well-defined intensely enhancing hypervascular mass in the masseter muscle as the initial presentation. We present the imaging findings of this case and a literature review about radiologic differential diagnosis of intramasseteric masses.

The influence of experimental interfering occlusal contacts on the postural activity of the anterior temporal and masseter muscles in young adults.

Science.gov (United States)

Riise, C; Sheikholeslam, A

1982-09-01

The effects of an intercuspal occlusal interference on the pattern of postural activity of the anterior temporal and masseter muscles were studied in eleven volunteers with complete, natural dentitions. The results indicate that, in man, there is postural activity in the anterior temporal and sometimes in the masseter muscles. The pattern of postural activity is influenced by the occurrence of an experimental occlusal interference, sometimes as early as 1 h after the insertion. After 48 h there was a significant increase of the activity in the anterior temporal muscles. This increased activity persisted until the interference was removed 1 week later and had almost disappeared 1 week after the removal.

Effect of experimental chewing on masticatory muscle pain onset

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Paulo César Rodrigues Conti

2011-02-01

Full Text Available OBJECTIVES: To evaluate the effect of a chewing exercise on pain intensity and pressure-pain threshold in patients with myofascial pain. METHODS: Twenty-nine consecutive women diagnosed with myofascial pain (MFP according to the Research Diagnostic Criteria comprised the experimental group and 15 healthy age-matched female were used as controls. Subjects were asked to chew a gum stick for 9 min and to stay at rest for another 9 min afterwards. Pain intensity was rated on a visual analog scale (VAS every 3 min. At 0, 9 and 18 min, the pressure-pain threshold (PPT was measured bilaterally on the masseter and the anterior, medium, and posterior temporalis muscles. RESULTS: Patients with myofascial pain reported increase (76% and no change (24% on the pain intensity measured with the VAS. A reduction of the PPT at all muscular sites after the exercise and a non-significant recovery after rest were also observed. CONCLUSION: The following conclusions can be drawn: 1. there are at least two subtypes of patients with myofascial pain that respond differently to experimental chewing; 2. the chewing protocol had an adequate discriminative ability in distinguishing patients with myofascial pain from healthy controls.

No effect of experimental occlusal interferences on pressure pain thresholds of the masseter and temporalis muscles in healthy women

NARCIS (Netherlands)

Michelotti, A; Farella, M; Steenks, MH; Gallo, LM; Palla, S

It has been suggested that occlusal interferences may lead to pain and tenderness of the masticatory muscles. Tender jaw muscles are more sensitive to pressure pain, as assessed by means of pressure algometry. We tested the effects of occlusal interferences on the pressure pain threshold of the jaw

Cysticercosis of masseter

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B Dilip Kumar

2011-01-01

Full Text Available Cysticercosis is a parasitic infestation caused by the larval stage of Taenia solium, a cestodic paratise. It is a common disease in developing countries where it is also endemic. The most commonly infested body organs include subcutaneous tissues, brain and skeletal muscles. It is interesting to note that oral lesion of cysticercosis is a rare event. Here we report an isolated lesion of cysticercosis in the masseter muscle.

The power features of Masseter muscle activity in tension-type and migraine without aura headache during open-close clench cycles

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Behrouz Alizadeh Savareh

2017-07-01

Full Text Available Introduction Different types of headaches and TMJ click influence the masseter muscle activity. The aim of this study was to assess the trend of energy level of the electromyography (EMG activity of the masseter muscle during open-close clench cycles in migraine without aura (MOA and tension-type headache (TTH with or without TMJ click. Methods Twenty-five women with MOA and twenty four women with TTH participated in the study. They matched with 25 healthy subjects, in terms of class of occlusion and prevalence of temporomandibular joint (TMJ with click. The EMG of both masseter muscles were recorded during open-close clench cycles at a rate of 80 cycles per minute for 15 seconds. The mouth opening was restricted to two centimeters by mandibular motion frame. Signal processing steps have been done on the EMG as: noise removing, smoothing, feature extraction, and statistical analyzing. The six statistical parameters of energy computed were mean, Variance, Skewness, Kurtosis, and first and second half energy over all signal energy. Results A three-way ANOVA indicated that during all the cycles, the mean of energy was more and there was a delay in showing the peak of energy in the masseter of the left side with clicked TMJ in MOA group compared to the two other groups, while this pattern occurred inversely in the side with no-clicked TMJ (P < 0.009. The variation of energy was significantly less in MOA group compared to the two other groups in the no-clicked TMJ (P < 0.003. However, the proportion of the first or second part of signal energy to all energy showed that TTH group had less energy in the first part and more energy in the second part in comparison to the two other groups (P < 0.05. Conclusion The study showed different changes in the energy distribution of masseter muscle activity during cycles in MOA and TTH. MOA, in contrast to TTH, had lateralization effect on EMG and interacted with TMJ click.

Jaw muscle pain and its effect on gothic arch tracings.

Science.gov (United States)

Obrez, A; Stohler, C S

1996-04-01

Perceived changes in occlusion and decreased range of motion are often expressed by patients with masticatory muscle pain. The adverse loading of craniomandibular tissues that results from an inadequate maxillomandibular relationship in combination with the coexisting dysfunction is widely regarded as the cause of pain. This study was designed to test whether pain can cause significant changes in position of the mandible and therefore form the basis for any perceived changes in the maxillomandibular relationship. A second objective was to determine whether pain can cause changes in the mandibular range of motion. Five subjects who rated pain intensity on a visual analog scale were used in a single-blind, randomized, repeated-measures study design. Tonic muscle pain was induced by infusion of 5% hypertonic saline solution into the central portion of the superficial masseter muscle. Isotonic saline solution was used as a control, with subjects blinded to the type of substance given. The effect of pain on the position of the apex of the gothic arch tracing, the direction of the lateral mandibular border movements, and the mandibular range of motion was studied in a horizontal plane with minimal occlusal separation. Pain significantly affected the position of the apex of the gothic arch tracing in anterior (F = 11.46, p = 0.03) and transverse (F = 35.0, p = 0.004) directions. Similarly, pain affected the orientation of the mandibular lateral border movements (F = 12.44, p = 0.02) and their magnitude (F = 14.97, p = 0.01). All pain-induced effects proved to be reversible. The observed effect of pain can explain the perceived change of bite that is frequently noted by patients with orofacial pain. This study provided evidence of an alternative causal relationship between pain and changes in occlusal relationship and questions occlusal therapy as treatment, directed toward the elimination of the underlying cause in patients with masticatory muscle pain.

Comparison of clinical marking and ultrasound-guided injection of Botulinum type A toxin into the masseter muscles for treating bruxism and its cosmetic effects.

Science.gov (United States)

Quezada-Gaon, Natacha; Wortsman, Ximena; Peñaloza, Osvaldo; Carrasco, Juan Eduardo

2016-09-01

Botulinum toxin type A has been used for treating the hypertrophy of the masseter muscles and its cosmetic effects. Ultrasound is increasingly used in dermatology, along with the guidance of mini-invasive procedures. To evaluate the role of ultrasound for guiding the application of Botulinum A toxin in patients with cosmetic alterations due to bruxism, correlate the clinical landmarks with the ultrasound findings, and study the effect on the symptoms, cosmetics, and quality of life. Twenty individuals with bruxism and cosmetic alterations underwent an ultrasound-guided injection of Botulinum toxin type A in each masseter muscle. Clinical and ultrasound marking of the procedure was compared. Clinical and sonographic evaluation was performed at the time of injection and 3 months later. Ten normal individuals underwent ultrasound of the masseter muscles as a control group. Up to 65% of individuals showed anatomical variants of the salivary glands. The method for clinically marking the skin showed a frequently erroneous location of the anterior point (up to 40% of cases) that was proven by ultrasound to be out of the muscle. In 20% of cases, ultrasound showed that the needle should be longer to enter the muscle. After injection, most of the patients demonstrated a decrease of the symptoms and cosmetic and quality of life improvements. Ultrasound can be a potent tool for guiding the injection of Botulinum toxin into the masseter muscles. It may contribute to a more personalized procedure, better cosmetic results, and help to avoid potential complications. © 2016 Wiley Periodicals, Inc.

Wearing of complete dentures reduces slow fibre and enhances hybrid fibre fraction in masseter muscle

Czech Academy of Sciences Publication Activity Database

Cvetko, E.; Karen, Petr; Eržen, I.

2012-01-01

Roč. 39, č. 8 (2012), s. 608-614 ISSN 0305-182X R&D Projects: GA MŠk(CZ) MEB090910; GA MŠk(CZ) LC06063 Institutional research plan: CEZ:AV0Z50110509 Keywords : human masseter * MyHC isoforms * muscle fibre types Subject RIV: FH - Neurology Impact factor: 2.344, year: 2012

APPLICATION OF MRI IN THE DIAGNOSTICS OF M. MASSETER

Directory of Open Access Journals (Sweden)

Mariana Dimova-Gabrovska

2017-06-01

Full Text Available Magnetic resonance imaging (MRI is a non-invasive diagnostic method which can provide detailed images of organs and structures of the human body. The purpose of this review is to explore and introduce the diagnostic capabilities of MRI in imaging m. masseter in conditions of norm and pathology. The material of the review is information of 20 literary sources selected from 530, found by keywordsfromJanuary to April 2017. The information about MRI imaging of the normal anatomy of m. masseter and the most common findings in muscle - muscle hypertrophy, inflammatory changes, vascular malformations, intramuscular hemangioma, cysticercosis and changes after radiotherapy was analyzed. In conclusion, the diagnostic capabilities of MRI of masseter muscle – both in the conditions of norm and pathology were confirmed. The method is considered to be reliable, objective, non-invasive and accurate.

A COMPARATIVE-STUDY OF ELECTROMYOGRAMS OF THE MASSETER, TEMPORALIS, AND ANTERIOR DIGASTRIC MUSCLES OBTAINED BY SURFACE AND INTRAMUSCULAR ELECTRODES - RAW-EMG

NARCIS (Netherlands)

KOOLE, P; DEJONGH, HJ; BOERING, G

Electromyographic activity was synchronously recorded by surface and intramuscular electrodes in the same muscle. The activity of the left masseter, left temporalis, and both bellies of the anterior digastric muscle was studied by this double registration technique. In rest position no

Sarcoglycan complex in masseter and sternocleidomastoid muscles of baboons: an immunohistochemical study

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G. Cutroneo

2015-06-01

Full Text Available The sarcoglycan complex consists of a group of single-pass transmembrane glycoproteins that are essential to maintain the integrity of muscle membranes. Any mutation in each sarcoglycan gene causes a series of recessive autosomal dystrophin-positive muscular dystrophies. Negative fibres for sarcoglycans have never been found in healthy humans and animals. In this study, we have investigated whether the social ranking has an influence on the expression of sarcoglycans in the skeletal muscles of healthy baboons. Biopsies of masseter and sternocleidomastoid muscles were processed for confocal immunohistochemical detection of sarcoglycans. Our findings showed that baboons from different social rankings exhibited different sarcoglycan expression profiles. While in dominant baboons almost all muscles were stained for sarcoglycans, only 55% of muscle fibres showed a significant staining. This different expression pattern is likely to be due to the living conditions of these primates. Sarcoglycans which play a key role in muscle activity by controlling contractile forces may influence the phenotype of muscle fibres, thus determining an adaptation to functional conditions. We hypothesize that this intraspecies variation reflects an epigenetic modification of the muscular protein network that allows baboons to adapt progressively to a different social status.

Assessment of pain sensitivity in patients with deep bite and sex- and age-matched controls

DEFF Research Database (Denmark)

Sonnesen, Ane Liselotte; Svensson, Peter

2011-01-01

AIMS: To compare pain sensitivity between deep bite patients and a sex- and age-matched control group with normal occlusion. METHODS: Pain sensitivity was assessed by injections of the excitatory amino acid glutamate into the masseter and brachioradialis muscles. Intensity of glutamate-evoked pai...... of gender-related differences in somatosensory sensitivity and for the first time indicate that subjects with deep bite may be more sensitive to glutamate-evoked pain and thermal stimuli.......AIMS: To compare pain sensitivity between deep bite patients and a sex- and age-matched control group with normal occlusion. METHODS: Pain sensitivity was assessed by injections of the excitatory amino acid glutamate into the masseter and brachioradialis muscles. Intensity of glutamate-evoked pain...

Effects of orthognathic surgery for class III malocclusion on signs and symptoms of temporomandibular disorders and on pressure pain thresholds of the jaw muscles.

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Farella, M; Michelotti, A; Bocchino, T; Cimino, R; Laino, A; Steenks, M H

2007-07-01

The aim of this longitudinal study was to determine the effects of orthognathic surgery on signs and symptoms of temporomandibular disorders (TMD) and on pressure pain thresholds (PPTs) of the jaw muscles. Fourteen consecutive class III patients undergoing pre-surgical orthodontic treatment were treated by combined Le Fort I osteotomy and bilateral sagittal ramus osteotomy. The clinical examination included the assessment of signs and symptoms of TMD and the assessment of PPTs of the masseter and temporalis muscles. Anamnestic, clinical and algometric data were collected during five sessions over a 1-year period. Seven out of 14 patients presented with disc displacement with reduction at baseline, whereas four patients (two of them were new cases) did so at the end of follow up (p>0.05). None of the patients were diagnosed with myofascial pain of the jaw muscles at the beginning or end of follow up. PPTs of the masseter and temporalis muscles did not change significantly from baseline values throughout the whole study period. The occurrence of signs and symptoms of TMD fluctuates with an unpredictable pattern after orthognathic surgery for class III malocclusions.

Masseter function and skeletal malocclusion.

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Sciote, J J; Raoul, G; Ferri, J; Close, J; Horton, M J; Rowlerson, A

2013-04-01

The aim of this work is to review the relationship between the function of the masseter muscle and the occurrence of malocclusions. An analysis was made of the masseter muscle samples from subjects who underwent mandibular osteotomies. The size and proportion of type-II fibers (fast) decreases as facial height increases. Patients with mandibular asymmetry have more type-II fibers on the side of their deviation. The insulin-like growth factor and myostatin are expressed differently depending on the sex and fiber diameter. These differences in the distribution of fiber types and gene expression of this growth factor may be involved in long-term postoperative stability and require additional investigations. Muscle strength and bone length are two genetically determined factors in facial growth. Myosin 1H (MYOH1) is associated with prognathia in Caucasians. As future objectives, we propose to characterize genetic variations using "Genome Wide Association Studies" data and their relationships with malocclusions. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Genetic response in masseter muscle after orthognathic surgery in comparison with healthy controls - A Microarray study.

Science.gov (United States)

Marewski, Maya; Petto, Carola; Schneider, Matthias; Harzer, Winfried

2017-04-01

One third of adult patients with orthognathic surgery of a prognathic or retrognathic mandible show relapse. The sagittal split osteotomy of the mandible leads to a displacement of both parts up to 10 mm without any changes of muscle attachment. Changed mandible length needs adaptation of muscle capacity because of changed force to moment ratio. The aim of this Microarray study was to analyze the general genetic response of masseter muscle in patients with retrognathism or prognathism of the mandible six months after surgery in comparison with healthy untreated controls. We found in tissue samples from masseter muscle a reduction of different entities between patients and controls but less in retrognathic than in prognathic patients (274/429). The different entities to controls in prognathia were reduced from 1862 to 1749 but increased in retrognathia from 1070 to 1563. We have to consider that the total amount of different entities to the controls is higher in patients with prognathic mandible (7364) because of their strong genetic controlled development compared with that in patients with retrognathic mandible (4126), which is more environmentally influenced. It can be concluded that function follows form after surgical change with high inheritance. In retrognathic patients the adaptation could be delayed or the capacity of regeneration potential is not sufficient. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Objective assessment of actual chewing side by measurement of bilateral masseter muscle electromyography.

Science.gov (United States)

Yamasaki, Yo; Kuwatsuru, Rika; Tsukiyama, Yoshihiro; Matsumoto, Hiroshi; Oki, Kyosuke; Koyano, Kiyoshi

2015-12-01

The aim of this study was to examine the validity of objective assessment of actual chewing side by measurement of electromyographic (EMG) activity of the bilateral masseter muscles upon chewing test foods. The sample consisted of 19 healthy, dentate individuals. The subjects were asked to chew three types of test foods (peanuts, beef jerky, and chewing gum) for 10 strokes on the right side and then on the left side, and instructed to perform maximum voluntary clenching for 3s, three times. EMG activity from the bilateral masseter muscles was recorded. The data were collected in three different days. The root mean square EMG amplitude obtained from the maximum clenching task was used as the maximum voluntary contraction (MVC). Then, the level of amplitude against the MVC (%MVC) was calculated for the right and left sides on each stroke. The side with the larger %MVC value was judged as the chewing side, and the concordance rates (CRs) for the instructed chewing side (ICS) and the judged chewing side (JCS) were calculated. Intraclass correlation coefficients (ICCs) of the CRs were calculated to evaluate the reproducibility of the method. High CRs between the ICS and JCS for each test food were recognized. There were significant ICCs for beef jerky (R=0.761, Pchewing gum (R=0.785, Pchewing side during mastication. Copyright © 2015 Elsevier Ltd. All rights reserved.

Heterogeneity among muscle precursor cells in adult skeletal muscles with differing regenerative capacities.

Science.gov (United States)

Pavlath, G K; Thaloor, D; Rando, T A; Cheong, M; English, A W; Zheng, B

1998-08-01

Skeletal muscle has a remarkable capacity to regenerate after injury, although studies of muscle regeneration have heretofore been limited almost exclusively to limb musculature. Muscle precursor cells in skeletal muscle are responsible for the repair of damaged muscle. Heterogeneity exists in the growth and differentiation properties of muscle precursor cell (myoblast) populations throughout limb development but whether the muscle precursor cells differ among adult skeletal muscles is unknown. Such heterogeneity among myoblasts in the adult may give rise to skeletal muscles with different regenerative capacities. Here we compare the regenerative response of a masticatory muscle, the masseter, to that of limb muscles. After exogenous trauma (freeze or crush injuries), masseter muscle regenerated much less effectively than limb muscle. In limb muscle, normal architecture was restored 12 days after injury, whereas in masseter muscle, minimal regeneration occurred during the same time period. Indeed, at late time points, masseter muscles exhibited increased fibrous connective tissue in the region of damage, evidence of ineffective muscle regeneration. Similarly, in response to endogenous muscle injury due to a muscular dystrophy, widespread evidence of impaired regeneration was present in masseter muscle but not in limb muscle. To explore the cellular basis of these different regenerative capacities, we analyzed the myoblast populations of limb and masseter muscles both in vivo and in vitro. From in vivo analyses, the number of myoblasts in regenerating muscle was less in masseter compared with limb muscle. Assessment of population growth in vitro indicated that masseter myoblasts grow more slowly than limb myoblasts under identical conditions. We conclude that the impaired regeneration in masseter muscles is due to differences in the intrinsic myoblast populations compared to limb muscles.

Role of cyclic AMP sensor Epac1 in masseter muscle hypertrophy and myosin heavy chain transition induced by β2-adrenoceptor stimulation.

Science.gov (United States)

Ohnuki, Yoshiki; Umeki, Daisuke; Mototani, Yasumasa; Jin, Huiling; Cai, Wenqian; Shiozawa, Kouichi; Suita, Kenji; Saeki, Yasutake; Fujita, Takayuki; Ishikawa, Yoshihiro; Okumura, Satoshi

2014-12-15

The predominant isoform of β-adrenoceptor (β-AR) in skeletal muscle is β2-AR and that in the cardiac muscle is β1-AR. We have reported that Epac1 (exchange protein directly activated by cAMP 1), a new protein kinase A-independent cAMP sensor, does not affect cardiac hypertrophy in response to pressure overload or chronic isoproterenol (isoprenaline) infusion. However, the role of Epac1 in skeletal muscle hypertrophy remains poorly understood. We thus examined the effect of disruption of Epac1, the major Epac isoform in skeletal muscle, on masseter muscle hypertrophy induced by chronic β2-AR stimulation with clenbuterol (CB) in Epac1-null mice (Epac1KO). The masseter muscle weight/tibial length ratio was similar in wild-type (WT) and Epac1KO at baseline and was significantly increased in WT after CB infusion, but this increase was suppressed in Epac1KO. CB treatment significantly increased the proportion of myosin heavy chain (MHC) IIb at the expense of that of MHC IId/x in both WT and Epac1KO, indicating that Epac1 did not mediate the CB-induced MHC isoform transition towards the faster isoform. The mechanism of suppression of CB-mediated hypertrophy in Epac1KO is considered to involve decreased activation of Akt signalling. In addition, CB-induced histone deacetylase 4 (HDAC4) phosphorylation on serine 246 mediated by calmodulin kinase II (CaMKII), which plays a role in skeletal muscle hypertrophy, was suppressed in Epac1KO. Our findings suggest that Epac1 plays a role in β2-AR-mediated masseter muscle hypertrophy, probably through activation of both Akt signalling and CaMKII/HDAC4 signalling. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

Influence of experimental interfering occlusal contacts on the activity of the anterior temporal and masseter muscles during submaximal and maximal bite in the intercuspal position.

Science.gov (United States)

Sheikholeslam, A; Riise, C

1983-05-01

The effects of an intercuspal occlusal interference on the pattern of activity of the anterior temporal and masseter muscles during submaximal and maximal bite, were studied in eleven volunteers with complete, natural dentitions. The results show that, during maximal and submaximal bite an occlusal interference (about 0.5 mm) in the intercuspal position is able to disturb the almost symmetric pattern of muscular activity in the anterior temporal and masseter muscles. Further, the level of muscular activity during maximal bite decreased significantly in all muscles studied. In some subjects, the decrease of muscular activity could still be observed one week after insertion of the interfering contact. After eliminating the interference, the muscular co-ordination pattern improved and the level of muscular activity increased significantly.

Treatment of chronic pain associated with nocturnal bruxism with botulinum toxin. A prospective and randomized clinical study

Science.gov (United States)

Al-Wayli, Hessa

2017-01-01

Background To evaluate the role of botulinum toxin type A (BTX-A) in the treatment of pain associated with nocturnal bruxism. Material and Methods Fifty subjects reporting nocturnal bruxism were recruited for a randomized clinical trial. Twenty five bruxers were injected with botulinum toxin in both masseters, and twenty five were treated with traditional methods of treating bruxism. Patients were evaluated at 3rd week, 2nd and 6th month and one year after injection and then used to calculate bruxism events. Bruxism symptoms were investigated using questionnaires. Results Mean pain score due to Bruxism events in the masseter muscle decreased significantly in the botulinum toxin injection group A (P =0.000, highly significant). However, in the conventional treatment group, mean pain score does not show improvement with time (p>0.05). Conclusions Our results suggest that botulinum toxin injection reduced the mean pain score and number of bruxism events, most likely by decreasing the muscle activity of masseter rather than affecting the central nervous system. Key words:Temporomandibular pain, nocturnal bruxism, botulinum toxin. PMID:28149474

Effects of phototherapy on muscle activity and pain in individuals with temporomandibular disorder: a study protocol for a randomized controlled trial.

Science.gov (United States)

Herpich, Carolina Marciela; Leal-Junior, Ernesto Cesar Pinto; Amaral, Ana Paula; Tosato, Juliana de Paiva; Glória, Igor Phillip dos Santos; Garcia, Marília Barbosa Santos; Barbosa, Bruno Roberto Borges; El Hage, Yasmin; Arruda, Éric Edmur Camargo; Gomes, Cid Ándre Fidelis de Paula; Rodrigues, Monique Sampaio; de Sousa, Dowglas Fernando Magalhães; de Carvalho, Paulo de Tarso Camillo; Bussadori, Sandra Kalil; Gonzalez, Tabajara de Oliveira; Politti, Fabiano; Biasotto-Gonzalez, Daniela Aparecida

2014-12-16

According to the International Association for the Study of Pain (IASP), the term temporomandibular disorder (TMD) regards a subgroup of orofacial pain, the symptoms of which include pain or discomfort in the temporomandibular joint, ears, masticatory muscles and neck on one or both sides, as well as joint sounds, limited mandibular movements or mandibular deviation and difficulties chewing. Phototherapy, such as low-level laser therapy (LLLT) and light-emitting diode (LED) therapy, is one of the resources used to treatment muscle pain. Thus, there is a need to investigate therapeutic resources that combine different wavelengths as well as different light sources (LLLT and LED) in the same apparatus. The aim of the proposed study is to evaluate the effects of four different doses of phototherapy on pain, activity of the masticatory muscles (masseter and bilateral anterior temporal) and joint mobility in individuals with temporomandibular disorder. A further aim is to determine the cumulative effect 24 and 48 hours after a single session. A placebo-controlled, double-blind, randomized, clinical trial will be carried out involving 72 women between 18 and 40 years of age with a diagnosis of myogenous TMD. The participants will then be randomly allocated to four groups totaling 18 individuals per group. Three groups will be submitted to a single session of phototherapy with different light sources, and one group will receive placebo therapy: Group A (2.62 Joules); Group B (5.24 Joules); Group C (7.86 Joules); and Group D (0 Joules). The following assessment tools will be administered on four separate occasions (baseline and immediately after, 24 h after and 48 h after phototherapy). Pain intensity will be assessed using the visual analog scale for pain, while pain thresholds will be determined using algometer, and electromyographic (EMG) analysis on the masseter and anterior temporal muscles. The study will contribute to the practice of the evidence-based use of

Reproducibility of estimation of blood flow in the human masseter muscle from measurements of 133Xe clearance

International Nuclear Information System (INIS)

Monteiro, A.A.; Kopp, S.

1989-01-01

The reproducibility of estimations of the masseter intramuscular blood flow (IMBF) was assessed bilaterally within and between clinical sessions. The 133 Xe clearance in nine normal individuals was measured before, during, and immediately after endurance of isometric contraction at an attempted level of 50% of maximum voluntary clenching contraction. An overall low reproducibility of the estimations was found. This result was probably caused by uncertainties about the excact site of intramuscular 133 Xe deposition, errors in assessment of the plots of clearance, and variabilities in the relative contraction levels sustained, especially in the overall muscle effort. In agreement with previous reports concerning other skeletal muscles, the 133 Xe clearance method provided inconsistent estimates of absolute values of IMBF also in this clinical setting. Although there was a high intra-individual variation in the relative level of isometric contraction sustained, the endurance test induced distinct changes in IMBF, among which the estimate of post-endurance hyperemia was the most consistent for each individual. Therefore, measurements of 133 Xe clearance seem to be useful to detect intra-induvidual changes in masseter IMBF resulting from isometric work. 21 refs

Changes in intramuscular cytokine levels during masseter inflammation in male and female rats

OpenAIRE

Niu, Katelyn Y.; Ro, Jin Y.

2010-01-01

The present study was conducted to examine cytokine profiles in the masseter muscle before and after complete Freund’s adjuvant (CFA)-induced inflammation and possible sex differences in the cytokine levels. Age matched male and female Sprague Dawley rats were injected with CFA in the mid-region of the masseter muscle. Muscle tissue surrounding the injection site was extracted 6 hrs, 1, 3 and 7 days after the injection to measure TNF-α, IL-1β, IL-6 and IL-4 levels with Luminex multi-analyte p...

Localised task-dependent motor-unit recruitment in the masseter.

Science.gov (United States)

Schindler, H J; Hellmann, D; Giannakopoulos, N N; Eiglsperger, U; van Dijk, J P; Lapatki, B G

2014-07-01

Localised motor-unit (MU) recruitment in the masseter was analysed in this study. We investigated whether differential activation behaviour, which has already been reported for distant masseter regions, can also be detected in small muscle subvolumes at the level of single MUs. Two bipolar fine-wire electrodes and an intra-oral 3D bite-force transmitter were used to record intra-muscular electromyograms (EMG) resulting from controlled bite-forces of 10 healthy human subjects (mean age 24.1 ± 1.2 years). Two-hundred and seventeen decomposed MUs were organised into localised MU task groups with different (P < 0.001) force-direction-specific behaviour. Proportions of MUs involved in one, two, three or four examined tasks were 46%, 31%, 18% and 5%, respectively. This study provides evidence of the ability of the neuromuscular system to modify the mechanical output of small masseter subvolumes by differential control of adjacent MUs belonging to distinct task groups. Localised differential activation behaviour of the masseter may be the crucial factor enabling highly flexible and efficient adjustment of the muscle activity in response to complex local biomechanical needs, for example, continually varying bite-forces during the demanding masticatory process. © 2014 John Wiley & Sons Ltd.

Avaliação eletromiográfica do músculo masseter em pessoas com paralisia facial periférica de longa duração Masseter muscle electromyographic assessment in subject with long lasting facial palsy

Directory of Open Access Journals (Sweden)

Adriana Rahal

2007-06-01

Full Text Available OBJETIVO: verificar a atividade elétrica do músculo masseter em pessoas com paralisia facial periférica de longa duração. MÉTODOS: participaram deste estudo seis sujeitos de ambos os sexos, com paralisia facial há pelo menos doze meses, sem queixas mastigatórias e sem disfunção temporomandibular e com pelo menos seis dentes em cada hemiarcada. Todos preencheram um questionário de anamnese e em seguida foram submetidos à eletromiografia de superfície dos masseteres de ambos os lados. As provas eletromiográficas foram: posição habitual com lábios fechados, apertamento dentário, mastigação habitual e unilateral à direita e à esquerda com uva passa. RESULTADOS: em todas as provas eletromiográficas não foram observadas diferenças significantes (p=0,05 entre os lados com e sem paralisia facial. CONCLUSÃO: observou-se com o presente estudo que a força do músculo masseter não sofre influência da paralisia facial de longa duração.PURPOSE: to check the masseter electrical activity in long lasting facial paralysis patients. METHODS: six subjects, with facial paralysis for over a period of twelve months, males and females, took part in this study. Patients should not show any masticatory complaints or have any diagnoses of temporo-mandibular joint dysfunction, having at least six teeth in each half dental ridge. All subjects filled out a questionnaire regarding oral habits and were assessed by surface electromyography of the masseter muscle of both sides. Electromyographic records were taken with lips closed at rest, teeth tightness, besides usual mastication, and unilateral mastication on both sides with raisins. RESULTS: in all electromyographic tests there were no statistically significant differences (p=0.05 between both sides, with and without facial paralysis. CONCLUSION: it was observed that the strength of the masseter muscle is not under the influence of long lasting facial paralysis.

Referred pain from myofascial trigger points in head and neck-shoulder muscles reproduces head pain features in children with chronic tension type headache.

Science.gov (United States)

Fernández-de-las-Peñas, César; Fernández-Mayoralas, Daniel M; Ortega-Santiago, Ricardo; Ambite-Quesada, Silvia; Palacios-Ceña, Domingo; Pareja, Juan A

2011-02-01

Our aim was to describe the referred pain pattern and areas from trigger points (TrPs) in head, neck, and shoulder muscles in children with chronic tension type headache (CTTH). Fifty children (14 boys, 36 girls, mean age: 8 ± 2) with CTTH and 50 age- and sex- matched children participated. Bilateral temporalis, masseter, superior oblique, upper trapezius, sternocleidomastoid, suboccipital, and levator scapula muscles were examined for TrPs by an assessor blinded to the children's condition. TrPs were identified with palpation and considered active when local and referred pains reproduce headache pain attacks. The referred pain areas were drawn on anatomical maps, digitalized, and also measured. The total number of TrPs was significantly greater in children with CTTH as compared to healthy children (P < 0.001). Active TrPs were only present in children with CTTH (P < 0.001). Within children with CTTH, a significant positive association between the number of active TrPs and headache duration (r (s) = 0.315; P = 0.026) was observed: the greater the number of active TrPs, the longer the duration of headache attack. Significant differences in referred pain areas between groups (P < 0.001) and muscles (P < 0.001) were found: the referred pain areas were larger in CTTH children (P < 0.001), and the referred pain area elicited by suboccipital TrPs was larger than the referred pain from the remaining TrPs (P < 0.001). Significant positive correlations between some headache clinical parameters and the size of the referred pain area were found. Our results showed that the local and referred pains elicited from active TrPs in head, neck and shoulder shared similar pain pattern as spontaneous CTTH in children, supporting a relevant role of active TrPs in CTTH in children.

Immediate changes in masticatory mechanosensitivity, mouth opening, and head posture after myofascial techniques in pain-free healthy participants: a randomized controlled trial.

Science.gov (United States)

Heredia-Rizo, Alberto Marcos; Oliva-Pascual-Vaca, Angel; Rodríguez-Blanco, Cleofás; Piña-Pozo, Fernando; Luque-Carrasco, Antonio; Herrera-Monge, Patricia

2013-06-01

This study aimed to assess the immediate effects on masticatory muscle mechanosensitivity, maximal vertical mouth opening (VMO), and head posture in pain-free healthy participants after intervention with myofascial treatment in the temporalis and masseter muscles. A randomized, double-blind study was conducted. The sample group included 48 participants (n=48), with a mean age of 21±2.47 years (18-29). Two subgroups were defined: an intervention group (n=24), who underwent a fascial induction protocol in the masseter and temporalis muscles, and a control group (n=24), who underwent a sham (placebo) intervention. The pressure pain threshold in 2 locations in the masseter (M1, M2) and temporalis (T1, T2) muscles, maximal VMO, and head posture, by means of the craniovertebral angle, were all measured. Significant improvements were observed in the intragroup comparison in the intervention group for the craniovertebral angle with the participant in seated (P.05). Myofascial induction techniques in the masseter and temporalis muscles show no significant differences in maximal VMO, in the mechanical sensitivity of the masticatory muscles, and in head posture in comparison with a placebo intervention in which the therapist's hands are placed in the temporomandibular joint region without exerting any therapeutic pressure. Copyright © 2013 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

[Changes of productions of energy metabolism in masseter of rats induced by occlusal interference].

Science.gov (United States)

Xu, X X; Cao, Y; Fu, K Y; Xie, Q F

2017-02-18

To investigate the effect of occlusal interference on the energy metabolism of masticatory muscle by studying the changes of adenosine triphosphate (ATP), adenosine diphosphate (ADP), inosine monophosphate (IMP), phosphocreatine, creatine, lactate and pH level in masseter muscles of rats after occlusal interference. Fifty male Sprague-Dawley rats were randomly assigned into experimental group (n=40) and control group (n=10). In experimental group, 0.4 mm thick metal crown was cemented to the upper right first molar of the rat, and maintained for 3, 7, 10, 14 d separately (n=10 for each time point). No occlusal interference was applied for control group. Bilateral masseter muscles of all the rats were acquired under general anesthesia. The samples of 5 rats in each group were fully homogenized with 0.4 mol/L perchlorate (10 mL/g). The homogenates were centrifuged, filtered and analyzed for ATP, ADP, IMP, phosphocreatine, creatine and lactate content by high performance liquid chromatography. The other samples in each group were mixed with homogenates containing 5 mmol/L sodium iodoacetate (10 mL/g), then homogenized and measured for pH value by pH meter in thermostatic water bathunder 37 degrees centigrade. Compared with control group, ATP content in bilateral masseter of the rats increased 3 d after occlusal interference [right side:(5.36±0.13) μmol/g,left side:(5.77±0.25) μmol/g] (Pocclusal interference (Pocclusal interference and maintained the low level on 10 and 14 d [right side:(10.70±0.71) μmol/g, (11.57±0.52) μmol/g, (10.74±1.39) μmol/g, left side:(10.05±0.57) μmol/g, (10.75±1.12)μmol/g, (10.61±1.15) μmol/g](Pocclusal interference was observed (P>0.05). Occlusal interference influences the content of energy metabolites in masticatory muscle of rats, which may be related to the pathological process of masticatory muscles induced by occlusal interference, such as muscle pain, dysfunction and altered fiber architecture.

Jaw Dysfunction Related to Pterygoid and Masseter Muscle Dosimetry After Radiation Therapy in Children and Young Adults With Head-and-Neck Sarcomas

International Nuclear Information System (INIS)

Krasin, Matthew J.; Wiese, Kristin M.; Spunt, Sheri L.; Hua, Chia-ho; Daw, Najat; Navid, Fariba; Davidoff, Andrew M.; McGregor, Lisa; Merchant, Thomas E.; Kun, Larry E.; McCrarey, Lola

2012-01-01

Purpose: To investigate the relationship between jaw function, patient and treatment variables, and radiation dosimetry of the mandibular muscles and joints in children and young adults receiving radiation for soft-tissue and bone sarcomas. Methods and Materials: Twenty-four pediatric and young adult patients with head-and-neck sarcomas were treated on an institutional review board−approved prospective study of focal radiation therapy for local tumor control. Serial jaw depression measurements were related to radiation dosimetry delivered to the medial and lateral pterygoid muscles, masseter muscles, and temporomandibular joints to generate mathematical models of jaw function. Results: Baseline jaw depression was only influenced by the degree of surgical resection. In the first 12 weeks from initiation of radiation, surgical procedures greater than a biopsy, administration of cyclophosphamide containing chemotherapy regimes, and large gross tumor volumes adversely affected jaw depression. Increasing dose to the pterygoid and masseter muscles above 40 Gy predicted loss of jaw function over the full course of follow-up. Conclusions: Clinical and treatment factors are related to initial and subsequent jaw dysfunction. Understanding these complex interactions and the affect of specific radiation doses may help reduce the risk for jaw dysfunction in future children and young adults undergoing radiation therapy for the management of soft-tissue and bone sarcomas.

Jaw Dysfunction Related to Pterygoid and Masseter Muscle Dosimetry After Radiation Therapy in Children and Young Adults With Head-and-Neck Sarcomas

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Krasin, Matthew J., E-mail: matthew.krasin@stjude.org [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, TN (United States); Wiese, Kristin M. [Department of Rehabilitation Services, St. Jude Children' s Research Hospital, Memphis, TN (United States); Spunt, Sheri L. [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States); Department of Pediatrics, University of Tennessee College of Medicine, Memphis, TN (United States); Hua, Chia-ho [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, TN (United States); Daw, Najat [Department of Pediatrics, University of Tennessee College of Medicine, Memphis, TN (United States); Department of Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States); Navid, Fariba [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States); Department of Pediatrics, University of Tennessee College of Medicine, Memphis, TN (United States); Davidoff, Andrew M. [Department of Surgery, St. Jude Children' s Research Hospital, Memphis, TN (United States); Department of Surgery, University of Tennessee College of Medicine, Memphis, TN (United States); McGregor, Lisa [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States); Department of Pediatrics, University of Tennessee College of Medicine, Memphis, TN (United States); Merchant, Thomas E.; Kun, Larry E. [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, TN (United States); McCrarey, Lola [Department of Rehabilitation Services, St. Jude Children' s Research Hospital, Memphis, TN (United States); and others

2012-01-01

Purpose: To investigate the relationship between jaw function, patient and treatment variables, and radiation dosimetry of the mandibular muscles and joints in children and young adults receiving radiation for soft-tissue and bone sarcomas. Methods and Materials: Twenty-four pediatric and young adult patients with head-and-neck sarcomas were treated on an institutional review board-approved prospective study of focal radiation therapy for local tumor control. Serial jaw depression measurements were related to radiation dosimetry delivered to the medial and lateral pterygoid muscles, masseter muscles, and temporomandibular joints to generate mathematical models of jaw function. Results: Baseline jaw depression was only influenced by the degree of surgical resection. In the first 12 weeks from initiation of radiation, surgical procedures greater than a biopsy, administration of cyclophosphamide containing chemotherapy regimes, and large gross tumor volumes adversely affected jaw depression. Increasing dose to the pterygoid and masseter muscles above 40 Gy predicted loss of jaw function over the full course of follow-up. Conclusions: Clinical and treatment factors are related to initial and subsequent jaw dysfunction. Understanding these complex interactions and the affect of specific radiation doses may help reduce the risk for jaw dysfunction in future children and young adults undergoing radiation therapy for the management of soft-tissue and bone sarcomas.

SURFACE ELECTROMYOGRAPHY OF MASSETER AND TEMPORAL MUSCLES WITH USE PERCENTAGE WHILE CHEWING ON CANDIDATES FOR GASTROPLASTY.

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Santos, Andréa Cavalcante Dos; Silva, Carlos Antonio Bruno da

Surface electromyography identifies changes in the electrical potential of the muscles during each contraction. The percentage of use is a way to treat values enabling comparison between groups. To analyze the electrical activity and the percentage of use of masseter and temporal muscles during chewing in candidates for gastric bypass. It was used Surface Electromyography Miotool 200,400 (Miotec (r), Porto Alegre/RS, Brazil) integrated with Miograph 2.0 software, involving patients between 20-40 years old. Were included data on electrical activity simultaneously and in pairs of temporal muscle groups and masseter at rest, maximum intercuspation and during the chewing of food previously classified. Were enrolled 39 patients (59 women), mean age 27.1+/-5.7. The percentage of use focused on temporal muscle, in a range of 11-20, female literacy (n=11; 47.82) on the left side and 15 (65.21) on the right-hand side. In the male, nine (56.25) at left and 12 (75.00) on the right-hand side. In masseter, also in the range of 11 to 20, female literacy (n=10; 43.48) on the left side and 11 (47.83) on the right-hand side. In the male, nine (56.25) at left and eight (50.00) on the right-hand side. 40-50% of the sample showed electrical activity in muscles (masseter and temporal) with variable values, and after processing into percentage value, facilitating the comparison of load of used electrical activity between the group, as well as usage percentage was obtained of muscle fibers 11-20% values involving, representing a range that is considered as a reference to the group studied. The gender was not a variable. A eletromiografia de superfície identifica variações dos potenciais elétricos dos músculos durante cada contração realizada. O percentual de uso é uma forma de tratar valores possibilitando comparação entre grupos. Analisar a atividade elétrica e o percentual de uso dos músculos masséteres e temporais durante a mastigação em candidatos à gastroplastia

Effect of a jig on EMG activity in different orofacial pain conditions.

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Bodere, Celine; Woda, Alain

2008-01-01

The bite stop (jig) is commonly used in clinical practice. It has been recommended as a simple means to routinely record or provide centric relation closure and, more recently, to reduce migraines and tension-type headaches. However, the reason for the jig effect has yet to be explained. This study tested the hypothesis that it works through a decrease in masticatory muscle activity. The effect of a jig placed on the maxillary anterior teeth was investigated by recording the electromyographic (EMG) activity of the superficial masseter and anterior temporal muscles at postural position and when swallowing on the jig. EMG recordings were obtained from 2 groups of pain patients (myofascial and neuropathic) and from 2 groups of pain-free patients (disc derangement and controls) unaware of the role of dental occlusion treatments. EMG activity in postural position was higher in pain groups than in pain-free groups. The jig strongly but temporarily decreased the postural EMG activity for masseter muscles in all groups except for the neuropathic group and for temporal muscles in the myofascial group. The EMG activity when swallowing with the jig was reduced in control, disc derangement, and myofascial groups; however, EMG "hyperactivity" in the neuropathic pain group seemed to be locked. The decrease of postural EMG activity, especially in the myofascial group, was short lasting and cannot be considered as evidence to support the hypothesis of a long-term muscle relaxation jig effect. However, the results may uphold certain short-term clinical approaches.

Headache attributed to masticatory myofascial pain: impact on facial pain and pressure pain threshold.

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Costa, Y M; Porporatti, A L; Stuginski-Barbosa, J; Bonjardim, L R; Speciali, J G; Conti, P C R

2016-03-01

There is no clear evidence on how a headache attributed to temporomandibular disorder (TMD) can hinder the improvement of facial pain and masticatory muscle pain. The aim of this study was to measure the impact of a TMD-attributed headache on masticatory myofascial (MMF) pain management. The sample was comprised of adults with MMF pain measured according to the revised research diagnostic criteria for temporomandibular disorders (RDC/TMD) and additionally diagnosed with (Group 1, n = 17) or without (Group 2, n = 20) a TMD-attributed headache. Both groups received instructions on how to implement behavioural changes and use a stabilisation appliance for 5 months. The reported facial pain intensity (visual analogue scale--VAS) and pressure pain threshold (PPT--kgf cm(-2)) of the anterior temporalis, masseter and right forearm were measured at three assessment time points. Two-way anova was applied to the data, considering a 5% significance level. All groups had a reduction in their reported facial pain intensity (P 0·100). A TMD-attributed headache in patients with MMF pain does not negatively impact pain management, but does change the pattern for muscle pain improvement. © 2015 John Wiley & Sons Ltd.

Downregulation of selective microRNAs in trigeminal ganglion neurons following inflammatory muscle pain

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Wei Dong

2007-06-01

Full Text Available Abstract Active regulation of gene expression in the nervous system plays an important role in the development and/or maintenance of inflammatory pain. MicroRNA (miRNA negatively regulates gene expression via posttranscriptional or transcriptional inhibition of specific genes. To explore the possible involvement of miRNA in gene regulation during inflammatory pain, we injected complete Freund's adjuvant (CFA unilaterally into the rat masseter muscle and quantified changes in neuron-specific mature miRNAs in the trigeminal ganglion (TG. Real-time reverse-transcription polymerase chain reaction revealed significant, but differential, downregulation of mature miR-10a, -29a, -98, -99a, -124a, -134, and -183 in the ipsilateral mandibular division (V3 of the TG within 4 hr after CFA. In contrast, levels of tested miRNAs did not change significantly in the contralateral V3 or the ipsilateral ophthalmic and maxillary divisions of the TG from inflamed rats, nor in the ipsilateral V3 of saline-injected animals. The downregulated miRNAs recovered differentially to a level equal to or higher than that in naive animals. Full recovery time varied with miRNA species but was at least 4 days. Expression and downregulation of some miRNAs were further confirmed by in situ hybridization of TG neurons that innervate the inflamed muscle. Although neurons of all sizes expressed these miRNAs, their signals varied between neurons. Our results indicate that miRNA species specific to neurons are quickly regulated following inflammatory muscle pain.

Isolated asymptomatic masseter muscle metastasis as first sign of metastatic disease in a patient with known melanoma

Directory of Open Access Journals (Sweden)

Caroline Asirvatham Gjorup

2016-12-01

Full Text Available A 65-year-old woman diagnosed with a nodular melanoma on the right shoulder had a PET/CT scan 13 months later demonstrating a FDG-avid mass in the left masseter muscle, which was asymptomatic and not clinically evident. Pathologic analysis confirmed metastasis of melanoma. Further subcutaneous, intramuscular and bone metastases developed and the patient was treated with surgery and immunotherapy. The patient is in complete-remission with no evident metastases seen on PET/CT 2.5 years after treatment with adoptive cell therapy using tumor-infiltrating lymphocytes (TIL therapy. Asymptomatic skeletal muscle metastases identified with PET/CT can have therapeutic and prognostic implications and a PET/CT scan should be performed as a true whole-body scan.

Comparative data from young men and women on masseter muscle fibres, function and facial morphology

DEFF Research Database (Denmark)

Tuxen, A.; Bakke, M.; Pinholt, E. M.

1999-01-01

The primary aim was to relate information about masseter muscle fibres and function to aspects of facial morphology in a group of healthy young men. The secondary aim was to investigate possible sex differences using data previously obtained from a comparable group of age-matched, healthy women......, and the tissue examined for myosin ATPase activity. Further, the cross-sectional areas of the different fibre types were measured. In spite of using age-matched healthy men and women with a full complement of teeth, statistically significant sex differences were found among measures related to muscle function...... and some measures of facial morphology. Thus data from men and women should not be pooled uncritically. The greater bite force in men than women corresponded with the greater diameter and cross-sectional area of type II fibres. Further, the males had more anteriorly inclined mandibles and shorter anterior...

Headache Exacerbates Pain Characteristics in Temporomandibular Disorders.

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Costa, Yuri Martins; Alves da Costa, Dayse Regina; de Lima Ferreira, Ana Paula; Porporatti, André Luís; Svensson, Peter; Rodrigues Conti, Paulo César; Bonjardim, Leonardo Rigoldi

2017-01-01

To evaluate the impact of headache in adults with masticatory myofascial pain (MMP) on the outcome variables clinical pain (ie, self-reported pain intensity and pressure pain sensitivity), sleep quality, and pain catastrophizing. A total of 97 patients with MMP were diagnosed with co-existing headache (MMPH group, n = 50) or without headache (MMP group, n = 47) according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The outcome parameters were the Pittsburgh Sleep Quality Index (PSQI); the Catastrophizing Thoughts subscale of the Pain-Related Self-Statement Scale (PRSS-C); pressure pain thresholds (PPTs) of the masseter and anterior temporalis muscles; and self-reported facial pain intensity measured on a 0- to 10-cm visual analog scale (VAS). Student t test for independent samples (α = 1.2%) and factorial analysis of variance (ANOVA) (α = 5%) were used to analyze the data. The MMPH group showed significantly impaired sleep quality (mean ± standard deviation [SD] PSQI score 9.1 ± 3.5) compared with the MMP group (7.2 ± 3.4; P = .008). Subscale scores on the PRSS-C were significantly higher in the MMPH (2.1 ± 1.2) than in the MMP group (1.6 ± 1.4, uncorrected P = .048). Also, the PPTs (kgf/cm²) of the masseter and anterior temporalis muscles were significantly lower in the MMPH group (1.52 ± 0.53; 1.29 ± 0.43, respectively) than in the MMP group (2.09 ± 0.73; 1.70 ± 0.68, respectively; P headache patients had lower PPTs in the anterior temporalis muscle (P = .041) in comparison with non-headache patients. Co-existence of headache further exacerbates clinical characteristics in patients with painful TMD, which implies involvement of common mechanisms and pathways of vulnerability in these patients.

Temporalis and masseter muscle activity in patients with anterior open bite and craniomandibular disorders

DEFF Research Database (Denmark)

Bakke, Merete; Michler, L

1991-01-01

values, particularly in subjects with muscular affection, but maximal activity increased significantly when biting on the splint. Maximal voluntary contraction was positively correlated to molar contact and negatively to anterior face height, mandibular inclination, vertical jaw relation and gonial angle......Activity in temporalis and masseter muscles, and traits of facial morphology and occlusal stability were studied in 22 patients (19 women, 3 men; 15-45 yr of age) with anterior open bite and symptoms and signs of craniomandibular disorders. Facial morphology was assessed by profile radiographs......, occlusal stability by tooth contacts, and craniomandibular function by clinical and radiological examination. Electromyographic activity was recorded by surface electrodes after primary treatment with a reflex-releasing, stabilizing splint. Maximal voluntary contraction was reduced compared to reference...

Compression-induced hyperaemia in the rabbit masseter muscle: a model to investigate vascular mechano-sensitivity of skeletal muscle

International Nuclear Information System (INIS)

Turturici, Marco; Roatta, Silvestro

2013-01-01

Recent evidence suggests that the mechano-sensitivity of the vascular network may underlie rapid dilatory events in skeletal muscles. Previous investigations have been mostly based either on in vitro or on whole-limb studies, neither preparation allowing one to assess the musculo-vascular specificity under physiological conditions. The aim of this work is to characterize the mechano-sensitivity of an exclusively-muscular vascular bed in vivo. In five anesthetized rabbits, muscle blood flow was continuously monitored in the masseteric artery, bilaterally (n = 10). Hyperaemic responses were evoked by compressive stimuli of different extent (50, 100 and 200 mm Hg) and duration (0.5, 1, 2 and 5 s) exerted by a servo-controlled motor on the masseter muscle. Peak amplitude of the hyperaemic response ranged from 340 ± 30% of baseline (at 50 mm Hg) to 459 ± 57% (at 200 mm Hg) (P < 0.05), did not depend on stimulus duration and exhibited very good reliability (ICC = 0.98) when reassessed at 30 min intervals. The time course of the response depended neither on applied pressure nor on the duration of the stimulus. In conclusion, for its high sensitivity and reliability this technique is adequate to characterize mechano-vascular reactivity and may prove useful in the investigation of the underlying mechanisms, with implications in the control of vascular tone and blood pressure in health and disease. (paper)

Experimental knee pain reduces muscle strength

DEFF Research Database (Denmark)

Henriksen, Marius; Mortensen, Sara Rosager; Aaboe, Jens

2011-01-01

Pain is the principal symptom in knee pathologies and reduced muscle strength is a common observation among knee patients. However, the relationship between knee joint pain and muscle strength remains to be clarified. This study aimed at investigating the changes in knee muscle strength following...... experimental knee pain in healthy volunteers, and if these changes were associated with the pain intensities. In a crossover study, 18 healthy subjects were tested on 2 different days. Using an isokinetic dynamometer, maximal muscle strength in knee extension and flexion was measured at angular velocities 0....... Knee pain reduced the muscle strength by 5 to 15% compared to the control conditions (P knee extension and flexion at all angular velocities. The reduction in muscle strength was positively correlated to the pain intensity. Experimental knee pain significantly reduced knee extension...

Bilateral experimental neck pain reorganize axioscapular muscle coordination and pain sensitivity.

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Christensen, S W; Hirata, R P; Graven-Nielsen, T

2017-04-01

Neck pain is a large clinical problem where reorganized trunk and axioscapular muscle activities have been hypothesised contributing to pain persistence and pain hypersensitivity. This study investigated the effects of bilateral experimental neck pain on trunk and axioscapular muscle function and pain sensitivity. In 25 healthy volunteers, bilateral experimental neck pain was induced in the splenius capitis muscles by hypertonic saline injections. Isotonic saline was used as control. In sitting, subjects performed slow, fast and slow-resisted unilateral arm movements before, during and after injections. Electromyography (EMG) was recorded from eight shoulder and trunk muscles bilaterally. Pressure pain thresholds (PPTs) were assessed bilaterally at the neck, head and arm. Data were normalized to the before-measures. Compared with control and post measurements, experimental neck pain caused (1) decreased EMG activity of the ipsilateral upper trapezius muscles during all but slow-resisted down movements (p neck pain reorganized axioscapular and trunk muscle activity together with local hyperalgesia and widespread hypoalgesia indicating that acute neck pain immediately affects trunk and axioscapular function which may affect both assessment and treatment. Bilateral clinical neck pain alters axioscapular muscle coordination but only effects of unilateral experimental neck pain has been investigated. Bilateral experimental neck pain causes task-dependent reorganized axioscapular and trunk muscle activity in addition to widespread decrease in pressure pain sensitivity. © 2016 European Pain Federation - EFIC®.

Small vertical changes in jaw relation affect motor unit recruitment in the masseter.

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Terebesi, S; Giannakopoulos, N N; Brüstle, F; Hellmann, D; Türp, J C; Schindler, H J

2016-04-01

Strategies for recruitment of masseter muscle motor units (MUs), provoked by constant bite force, for different vertical jaw relations have not previously been investigated. The objective of this study was to analyse the effect of small changes in vertical jaw relation on MU recruitment behaviour in different regions of the masseter during feedback-controlled submaximum biting tasks. Twenty healthy subjects (mean age: 24·6 ± 2·4 years) were involved in the investigation. Intra-muscular electromyographic (EMG) activity of the right masseter was recorded in different regions of the muscle. MUs were identified by the use of decomposition software, and root-mean-square (RMS) values were calculated for each experimental condition. Six hundred and eleven decomposed MUs with significantly (P recruitment behaviour were organised into localised MU task groups. MUs with different task specificity in seven examined tasks were observed. The RMS EMG values obtained from the different recording sites were also significantly (P recruitment was significantly (P recruited MUs and the RMS EMG values decreased significantly (P recruitment behaviour in discrete subvolumes of the masseter in response to small changes in vertical jaw relations. These fine-motor skills might be responsible for its excellent functional adaptability and might also explain the successful management of temporomandibular disorder patients by somatic intervention, in particular by the use of oral splints. © 2015 John Wiley & Sons Ltd.

Masticatory muscle activity during deliberately performed oral tasks

International Nuclear Information System (INIS)

Farella, M; Palla, S; Erni, S; Gallo, L M; Michelotti, A

2008-01-01

The aim of this study was to investigate masticatory muscle activity during deliberately performed functional and non-functional oral tasks. Electromyographic (EMG) surface activity was recorded unilaterally from the masseter, anterior temporalis and suprahyoid muscles in 11 subjects (5 men, 6 women; age = 34.6 ± 10.8 years), who were accurately instructed to perform 30 different oral tasks under computer guidance using task markers. Data were analyzed by descriptive statistics, repeated measurements analysis of variance (ANOVA) and hierarchical cluster analysis. The maximum EMG amplitude of the masseter and anterior temporalis muscles was more often found during hard chewing tasks than during maximum clenching tasks. The relative contribution of masseter and anterior temporalis changed across the tasks examined (F ≥ 5.2; p ≤ 0.001). The masseter muscle was significantly (p ≤ 0.05) more active than the anterior temporalis muscle during tasks involving incisal biting, jaw protrusion, laterotrusion and jaw cupping, the difference being statistically significant (p ≤ 0.05). The anterior temporalis muscle was significantly (p ≤ 0.01) more active than the masseter muscle during tasks performed in intercuspal position, during tooth grinding, and during hard chewing on the working side. Based upon the relative contribution of the masseter, anterior temporalis, and suprahyoid muscles, the investigated oral tasks could be grouped into six separate clusters. The findings provided further insight into muscle- and task-specific EMG patterns during functional and non-functional oral behaviors

Effect of hypnosis on masseter EMG recorded during the 'resting' and a slightly open jaw posture.

Science.gov (United States)

Al-Enaizan, N; Davey, K J; Lyons, M F; Cadden, S W

2015-11-01

The aim of this experimental study was to determine whether minimal levels of electromyographic activity in the masseter muscle are altered when individuals are in a verified hypnotic state. Experiments were performed on 17 volunteer subjects (8 male, 9 female) all of whom gave informed consent. The subjects were dentate and had no symptoms of pain or masticatory dysfunction. Surface electromyograms (EMGs) were made from the masseter muscles and quantified by integration following full-wave rectification and averaging. The EMGs were obtained (i) with the mandible in 'resting' posture; (ii) with the mandible voluntarily lowered (but with the lips closed); (iii) during maximum voluntary clenching (MVC). The first two recordings were made before, during and after the subjects were in a hypnotic state. Susceptibility to hypnosis was assessed with Spiegel's eye-roll test, and the existence of the hypnotic state was verified by changes in ventilatory pattern. On average, EMG levels expressed as percentages of MVC were less: (i) when the jaw was deliberately lowered as opposed to being in the postural position: (ii) during hypnosis compared with during the pre- and post-hypnotic periods. However, analysis of variance followed by post hoc tests with multiple comparison corrections (Bonferroni) revealed that only the differences between the level during hypnosis and those before and after hypnosis were statistically significant (P hypnosis, it appears that part of that EMG is of biological origin. © 2015 John Wiley & Sons Ltd.

Painful unilateral temporalis muscle enlargement: reactive masticatory muscle hypertrophy.

Science.gov (United States)

Katsetos, Christos D; Bianchi, Michael A; Jaffery, Fizza; Koutzaki, Sirma; Zarella, Mark; Slater, Robert

2014-06-01

An instance of isolated unilateral temporalis muscle hypertrophy (reactive masticatory muscle hypertrophy with fiber type 1 predominance) confirmed by muscle biopsy with histochemical fiber typing and image analysis in a 62 year-old man is reported. The patient presented with bruxism and a painful swelling of the temple. Absence of asymmetry or other abnormalities of the craniofacial skeleton was confirmed by magnetic resonance imaging and cephalometric analyses. The patient achieved symptomatic improvement only after undergoing botulinum toxin injections. Muscle biopsy is key in the diagnosis of reactive masticatory muscle hypertrophy and its distinction from masticatory muscle myopathy (hypertrophic branchial myopathy) and other non-reactive causes of painful asymmetric temporalis muscle enlargement.

Kinesthetic illusions attenuate experimental muscle pain, as do muscle and cutaneous stimulation.

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Gay, André; Aimonetti, Jean-Marc; Roll, Jean-Pierre; Ribot-Ciscar, Edith

2015-07-30

In the present study, muscle pain was induced experimentally in healthy subjects by administrating hypertonic saline injections into the tibialis anterior (TA) muscle. We first aimed at comparing the analgesic effects of mechanical vibration applied to either cutaneous or muscle receptors of the TA or to both types simultaneously. Secondly, pain alleviation was compared in subjects in whom muscle tendon vibration evoked kinesthetic illusions of the ankle joint. Muscle tendon vibration, which primarily activated muscle receptors, reduced pain intensity by 30% (p<0.01). In addition, tangential skin vibration reduced pain intensity by 33% (p<0.01), primarily by activating cutaneous receptors. Concurrently stimulating both sensory channels induced stronger analgesic effects (-51%, p<0.01), as shown by the lower levels of electrodermal activity. The strongest analgesic effects of the vibration-induced muscle inputs occurred when illusory movements were perceived (-38%, p=0.01). The results suggest that both cutaneous and muscle sensory feedback reduce muscle pain, most likely via segmental and supraspinal processes. Further clinical trials are needed to investigate these new methods of muscle pain relief. Copyright © 2015 Elsevier B.V. All rights reserved.

Neuropathic pain-like alterations in muscle nociceptor function associated with vibration-induced muscle pain.

Science.gov (United States)

Chen, Xiaojie; Green, Paul G; Levine, Jon D

2010-11-01

We recently developed a rodent model of the painful muscle disorders induced by occupational exposure to vibration. In the present study we used this model to evaluate the function of sensory neurons innervating the vibration-exposed gastrocnemius muscle. Activity of 74 vibration-exposed and 40 control nociceptors, with mechanical receptive fields in the gastrocnemius muscle, were recorded. In vibration-exposed rats ∼15% of nociceptors demonstrated an intense and long-lasting barrage of action potentials in response to sustained suprathreshold mechanical stimulation (average of 2635 action potentials with frequency of ∼44Hz during a 1min suprathreshold stimulus) much greater than that has been reported to be produced even by potent inflammatory mediators. While these high-firing nociceptors had lower mechanical thresholds than the remaining nociceptors, exposure to vibration had no effect on conduction velocity and did not induce spontaneous activity. Hyperactivity was not observed in any of 19 neurons from vibration-exposed rats pretreated with intrathecal antisense for the IL-6 receptor subunit gp130. Since vibration can injure peripheral nerves and IL-6 has been implicated in painful peripheral neuropathies, we suggest that the dramatic change in sensory neuron function and development of muscles pain, induced by exposure to vibration, reflects a neuropathic muscle pain syndrome. Copyright © 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Muscle activation during selected strength exercises in women with chronic neck muscle pain

DEFF Research Database (Denmark)

Andersen, Lars L; Kjaer, Michael; Andersen, Christoffer H

2008-01-01

selected strengthening exercises in women undergoing rehabilitation for chronic neck muscle pain (defined as a clinical diagnosis of trapezius myalgia). SUBJECTS: The subjects were 12 female workers (age=30-60 years) with a clinical diagnosis of trapezius myalgia and a mean baseline pain intensity of 5......BACKGROUND AND PURPOSE: Muscle-specific strength training has previously been shown to be effective in the rehabilitation of chronic neck muscle pain in women. The aim of this study was to determine the level of activation of the neck and shoulder muscles using surface electromyography (EMG) during...... muscle pain. Several of the strength exercises had high activation of neck and shoulder muscles in women with chronic neck pain. These exercises can be used equally in the attempt to achieve a beneficial treatment effect on chronic neck muscle pain....

Muscle activity pattern dependent pain development and alleviation.

Science.gov (United States)

Sjøgaard, Gisela; Søgaard, Karen

2014-12-01

Muscle activity is for decades considered to provide health benefits irrespectively of the muscle activity pattern performed and whether it is during e.g. sports, transportation, or occupational work tasks. Accordingly, the international recommendations for public health-promoting physical activity do not distinguish between occupational and leisure time physical activity. However, in this body of literature, attention has not been paid to the extensive documentation on occupational physical activity imposing a risk of impairment of health - in particular musculoskeletal health in terms of muscle pain. Focusing on muscle activity patterns and musculoskeletal health it is pertinent to elucidate the more specific aspects regarding exposure profiles and body regional pain. Static sustained muscle contraction for prolonged periods often occurs in the neck/shoulder area during occupational tasks and may underlie muscle pain development in spite of rather low relative muscle load. Causal mechanisms include a stereotype recruitment of low threshold motor units (activating type 1 muscle fibers) characterized by a lack of temporal as well as spatial variation in recruitment. In contrast during physical activities at leisure and sport the motor recruitment patterns are more dynamic including regularly relatively high muscle forces - also activating type 2 muscles fibers - as well as periods of full relaxation even of the type 1 muscle fibers. Such activity is unrelated to muscle pain development if adequate recovery is granted. However, delayed muscle soreness may develop following intensive eccentric muscle activity (e.g. down-hill skiing) with peak pain levels in thigh muscles 1-2 days after the exercise bout and a total recovery within 1 week. This acute pain profile is in contrast to the chronic muscle pain profile related to repetitive monotonous work tasks. The painful muscles show adverse functional, morphological, hormonal, as well as metabolic characteristics. Of

Experimental occlusal interference induces long-term masticatory muscle hyperalgesia in rats.

Science.gov (United States)

Cao, Ye; Xie, Qiu-Fei; Li, Kai; Light, Alan R; Fu, Kai-Yuan

2009-08-01

Temporomandibular joint or related masticatory muscle pain represents the most common chronic orofacial pain condition. Patients frequently report this kind of pain after dental alterations in occlusion. However, lack of understanding of the mechanisms of occlusion-related temporomandibular joint and muscle pain prevents treating this problem successfully. To explore the relationship between improper occlusion (occlusal interference) and masticatory muscle pain, we created an occlusal interference animal model by directly bonding a crown to a maxillary molar to raise the masticating surface of the tooth in rats. We raised the occlusal surface to three different heights (0.2, 0.4, and 0.6mm), and for one month we quantitatively measured mechanical nociceptive thresholds of the temporal and masseter muscles on both sides. Results showed a stimulus-response relationship between the height of occlusal interference and muscle hyperalgesia. Removal of the crown 6 days after occlusal interference showed that the removal at this time could not terminate the 1 month duration of mechanical hyperalgesia in the masticatory muscles. Lastly, we systemically administered NMDA antagonist MK801 (0.2, 0.1, and 0.05 mg/kg) to the treated rats and found that MK801 dose dependently attenuated the occlusal interference-induced hyperalgesia. These findings suggest that occlusal interference is directly related to masticatory muscle pain, and that central sensitization mechanisms are involved in the maintenance of the occlusal interference-induced mechanical hyperalgesia.

CONTRACTION CHARACTERISTICS AND MYOSIN HEAVY-CHAIN COMPOSITION OF RABBIT MASSETER MOTOR UNITS

NARCIS (Netherlands)

KWA, SHS; WEIJS, WA; JUCH, PJW

1. We studied isometric twitch peak force (TPF) and twitch contraction time (TCT) of 249 motor units of the masseter muscle in 41 rabbits after extracellular electrical stimulation of single trigeminal motoneurons in the brain stem. In 41 of these units we determined the amount of tension decrease

Atividade eletromiográfica dos músculos temporal anterior e masseter em crianças respiradoras bucais e em respiradoras nasais Electrical Activity of the Anterior Temporal and Masseter Muscles in Mouth and Nasal Breathing Children

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Aline Ferla

2008-08-01

Full Text Available A respiração bucal tem sido estudada por causar sérios efeitos no desenvolvimento do sistema estomatognático. OBJETIVO: Estudar, através da análise eletromiográfica, o padrão de atividade elétrica dos músculos temporal anterior e masseter em crianças com respiração bucal, comparando-os com o de crianças com respiração nasal. MATERIAL E MÉTODO: Foram estudados dois grupos de crianças: 17 respiradoras bucais (RB e 12 respiradoras nasais (RN. As crianças foram submetidas à avaliação eletromiográfica bilateral dos músculos supracitados nas situações de máxima intercuspidação e mastigação habitual. Utilizou-se o eletromiógrafo Myosystem Br-1, com 12 canais de aquisição, amplificação com ganho total de 5938, taxa de aquisição de 4000Hz e filtro passa-faixa de 20-1000Hz. O sinal foi processado em RMS, mensurado em µV e analisado e expresso em %, normalizado. Os dados foram tratados estatisticamente através do Teste t (Student. RESULTADOS: Observou-se que o nível de atividade elétrica do grupo RB foi inferior para todos os músculos e estatisticamente significante somente para o temporal esquerdo; os respiradores bucais apresentaram predomínio de atividade elétrica no lado direito e no músculo temporal durante a mastigação habitual. CONCLUSÃO: A respiração bucal interferiu na atividade elétrica dos músculos estudados nas situações funcionais de máxima intercuspidação e mastigação habitual.Mouth breathing has been associated with severe impact on the development of the stomatognathic system. AIM: This paper aims to analyze the electromyographical findings and patterns of electrical activity of the anterior temporal and masseter muscles in mouth and nasal breathing children. MATERIAL AND METHOD: The patients were divided into two groups: mouth breathers (n=17 and nasal breathers (n=12. The children underwent bilateral electromyographic examination of the anterior temporal and masseter muscles at

Effect of clenching on T2 and diffusion parameters of the masseter muscle

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Chikui, Toru; Kawazu, Toshiyuki; Kami, Yukiko; Yoshiura, Kazunori (Dept. of Oral and Maxillofacial Radiology, Faculty of Dental Science, Kyushu Univ., Fukuoka (Japan)), e-mail: chikui@rad.dent.kyushu-u.ac.jp; Shiraishi, Tomoko; Yuasa, Kenji (Section of Image Diagnosis, Dept. of Diagnostics and General Care, Fukuoka Dental College, Fukuoka (Japan)); Ichihara, Takahiro (Dept. of Radiology, Fukuoka Dental College Medical and Dental Hospital, Fukuoka (Japan)); Hatakenaka, Masamitsu (Dept. of Clinical Radiology, Faculty of Medical Science, Kyushu Univ., Fukuoka (Japan))

2010-01-15

Background: Persistent muscle contractions during clenching are considered to be one reason for temporomandibular disorders. However, no report has evaluated the effect of clenching on the masticatory muscles, as measured by magnetic resonance imaging (MRI). Purpose: To investigate whether clenching has an effect on either T2 or the coefficients for diffusion of the masseter muscles (MM), and to evaluate the effect of the distribution of bite force on such indices. Material and Methods: Twenty-three subjects were examined. Bite force was measured by a pressure-sensitive sheet, and the force of the right and the left sides was calculated. MRI was used to evaluate T2, the apparent diffusion coefficient (ADC), and the primary (1), secondary (2), and tertiary eigenvalues (3). These indices on the stronger side of the bite force were compared to those on the weaker side. Thereafter, the indices were compared between at rest and during clenching. Results: There was no significant difference in any of the indices (T2, ADC, 1, 2, and 3) between the side of stronger bite force and the side with weaker. T2 increased by clenching, and the difference was significant in the side with stronger bite force (P = 0.006). ADC, 1, 2, and 3 increased significantly by clenching (P <0.01, P <0.01, P <0.01, and P <0.01, respectively) on both sides. The percentage of change of 2 by clenching was 26.2+-15.7% on the stronger side and 26.9+-18.6% on the weaker side, which was significantly greater than either that of 1 or 3. Conclusion: The coefficients for diffusion of the MM were sensitive to change by clenching, and 2 was the most sensitive. Moreover, the relative distribution of the bite forces had no effect on any of the indices

Scapulothoracic muscle strength in individuals with neck pain.

Science.gov (United States)

Petersen, Shannon M; Domino, Nathan A; Cook, Chad E

2016-08-10

People with neck pain often present with weakness in the scapulothoracic muscles. Few studies have examined lower trapezius (LT), middle trapezius (MT) and serratus anterior (SA) muscle strength in individuals with neck pain, nor compared strength to asymptomatic individuals. The aim of this study was to examine LT, MT and SA muscle strength in individuals with chronic neck pain. Descriptive cross sectional design. Twenty two individuals with chronic neck pain and 17 asymptomatic individuals were included. Participants were asked to complete a screening questionnaire, Neck Disability Index, and underwent manual muscle testing for the LT, MT, and SA muscles bilaterally. Data analyses included paired and comparative independent t-tests. For individuals with neck pain, significant within subject differences in strength between sides for the LT (Pneck pain were significantly weaker than asymptomatic individuals for the LT (p= 0.02), MT (p= 0.03), and SA (p= 0.01) on their side of neck pain, but not on their non-painful side. Significant within subject differences were found between sides for the LT and MT while significant between group differences were identified for all three muscles tested.

Influence of experimental interfering occlusal contacts on the activity of the anterior temporal and masseter muscles during mastication.

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Riise, C; Sheikholeslam, A

1984-07-01

Quantitative electromyography (EMG) was used to study, in eleven volunteers with complete, natural dentitions, the effects of an experimental intercuspal occlusal interference on the pattern of activity of the anterior temporal and masseter muscles during mastication. The results show that a small occlusal interference (about 0.5 mm) in the intercuspal position can change the co-ordination of muscular activity during mastication. In general, there was a prolonged contraction time as well as a reduction of the activity in all the investigated elevators, especially on the side of the interference. Furthermore, after 48 h several subjects preferred to chew unilaterally. After removal of the interference, the pattern of co-ordination of muscular activity returned almost to the pre-experimental pattern within 2 weeks.

Influence of a scheduled-waiting task on EMG reactivity and oral habits among facial pain patients and no-pain controls.

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Nicholson, R A; Townsend, D R; Gramling, S E

2000-12-01

Recent research has strongly implicated the role of psychological stress in the development of temporomandibular disorders (TMD). It is widely reported that oral habits (e.g., teeth grinding) probably provide a behavioral link between stress and the development of TMD symptomatology. Extrapolation of research in the field of adjunctive behavior to the TMD disorders suggests that oral behaviors may develop conjointly with fixed-time (FT) stimulus presentation. The current experiment extended previous research examining this possibility by assessing the influence of experimental stress on masseter EMG and oral habits among persons who met broadband criteria for TMD and no-pain controls. Oral habit activity was assessed via self-report questionnaire whereas masseter muscle activity was measured continuously via electromyography across four phases (Adaptation, Free-Play, Scheduled-Play, Recovery). The Scheduled-Play phase was designed as a stress-reactivity task that included an FT schedule. Results indicated that, consistent with the stress-reactivity model, the Scheduled-Play phase resulted in a significant increase in masseter EMG levels relative to Free-Play and Adaptation, and that this effect was significantly larger for the TMD group relative to controls. The results suggest an adjunctive behavior effect although the effect was not specific to those with facial pain. Oral habit data showed a significant phase effect with oral habits that was significantly higher during the Scheduled-Play phase relative to Adaptation. The findings are the impetus for further study regarding the mechanisms whereby oral habits are developed and maintained despite their painful consequences.

Facial reanimation by muscle-nerve neurotization after facial nerve sacrifice. Case report.

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Taupin, A; Labbé, D; Babin, E; Fromager, G

2016-12-01

Recovering a certain degree of mimicry after sacrifice of the facial nerve is a clinically recognized finding. The authors report a case of hemifacial reanimation suggesting a phenomenon of neurotization from muscle-to-nerve. A woman benefited from a parotidectomy with sacrifice of the left facial nerve indicated for recurrent tumor in the gland. The distal branches of the facial nerve, isolated at the time of resection, were buried in the masseter muscle underneath. The patient recovered a voluntary hémifacial motricity. The electromyographic analysis of the motor activity of the zygomaticus major before and after block of the masseter nerve showed a dependence between mimic muscles and the masseter muscle. Several hypotheses have been advanced to explain the spontaneous reanimation of facial paralysis. The clinical case makes it possible to argue in favor of muscle-to-nerve neurotization from masseter muscle to distal branches of the facial nerve. It illustrates the quality of motricity that can be obtained thanks to this procedure. The authors describe a simple implantation technique of distal branches of the facial nerve in the masseter muscle during a radical parotidectomy with facial nerve sacrifice and recovery of resting tone but also a quality voluntary mimicry. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

The influence of experimentally induced pain on shoulder muscle activity

DEFF Research Database (Denmark)

Diederichsen, L.P.; Winther, A.; Dyhre-Poulsen, P.

2009-01-01

healthy men (range 22-27 years), with no history of shoulder or cervical problems, were included in the study. Pain was induced by 5% hypertonic saline injections into the supraspinatus muscle or subacromially. Seated in a shoulder machine, subjects performed standardized concentric abduction (0A degrees......Muscle function is altered in painful shoulder conditions. However, the influence of shoulder pain on muscle coordination of the shoulder has not been fully clarified. The aim of the present study was to examine the effect of experimentally induced shoulder pain on shoulder muscle function. Eleven...... muscles. EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper...

AN ELECTROMYOGRAPHIC STUDY OF WHETHER THE DIGASTRIC MUSCLES ARE CONTROLLED BY JAW-CLOSING PROPRIOCEPTORS IN MAN

NARCIS (Netherlands)

VANWILLIGEN, JD; MORIMOTO, T; BROEKHUIJSEN, ML; BIJL, GK; INOUE, T

Whether in the oral system the digastric muscles (which lack muscle spindles) are under the control of proprioceptive information from the masseter muscles (which contain muscle spindles) was investigated by analysing whether and how the masseters and digastrics showed coordinated behaviour during a

Masticatory Muscle Sleep Background EMG Activity is Elevated in Myofascial TMD Patients

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Raphael, Karen G.; Janal, Malvin N.; Sirois, David A.; Dubrovsky, Boris; Wigren, Pia E.; Klausner, Jack J.; Krieger, Ana C.; Lavigne, Gilles J.

2013-01-01

Despite theoretical speculation and strong clinical belief, recent research using laboratory polysomnographic (PSG) recording has provided new evidence that frequency of sleep bruxism (SB) masseter muscle events, including grinding or clenching of the teeth during sleep, is not increased for women with chronic myofascial temporomandibular disorder (TMD). The current case-control study compares a large sample of women suffering from chronic myofascial TMD (n=124) with a demographically matched control group without TMD (n=46) on sleep background electromyography (EMG) during a laboratory PSG study. Background EMG activity was measured as EMG root mean square (RMS) from the right masseter muscle after lights out. Sleep background EMG activity was defined as EMG RMS remaining after activity attributable to SB, other orofacial activity, other oromotor activity and movement artifacts were removed. Results indicated that median background EMG during these non SB-event periods was significantly higher (pcases exceeding control activity. Moreover, for TMD cases, background EMG was positively associated and SB event-related EMG was negatively associated with pain intensity ratings (0–10 numerical scale) on post sleep waking. These data provide the foundation for a new focus on small, but persistent, elevations in sleep EMG activity over the course of the night as a mechanism of pain induction or maintenance. PMID:24237356

Jaw muscles in older overdenture patients.

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Newton, James P; McManus, Frank C; Menhenick, Stephen

2004-03-01

To determine, using computer tomography (CT), whether the retention of a small number of teeth in the older adult used to support overdentures could affect the cross-sectional area (CSA) and X-ray density of two jaw closing muscles. Cross-sectional study of a group of older patients subdivided into dentate, edentulous and those wearing overdentures supported by two to five teeth. The sample consisted of 24 subjects aged 55-68 years. CSA and X-ray density of two jaw closing muscles, masseter and medial pterygoid were measured and evaluated using CT. There were no significant differences between left and right jaw muscles, but the CSA of the masseter muscles were significantly larger than the medial pterygoid muscles. The CSA of the masseter and medial pterygoid muscles was significantly smaller in edentulous subjects compared with dentate subjects but no significant difference was observed between subjects wearing overdentures and those with a natural dentition. No significant differences were observed with the X-ray density between different muscles or dental states. The retention of a small number of teeth in the older adult used to support overdentures appears to sustain the CSA of two jaw closing muscles and therefore could enhance these patients' masticatory ability compared with those who were edentulous.

Effects of experimental muscle pain on muscle activity and co-ordination during static and dynamic motor function.

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Graven-Nielsen, T; Svensson, P; Arendt-Nielsen, L

1997-04-01

The relation between muscle pain, muscle activity, and muscle co-ordination is still controversial. The present human study investigates the influence of experimental muscle pain on resting, static, and dynamic muscle activity. In the resting and static experiments, the electromyography (EMG) activity and the contraction force of m. tibialis anterior were assessed before and after injection of 0.5 ml hypertonic saline (5%) into the same muscle. In the dynamic experiment, injections of 0.5 ml hypertonic saline (5%) were performed into either m. tibialis anterior (TA) or m. gastrocnemius (GA) and the muscle activity and co-ordination were investigated during gait on a treadmill by EMG recordings from m. TA and m. GA. At rest no evidence of EMG hyperactivity was found during muscle pain. The maximal voluntary contraction (MVC) during muscle pain was significantly lower than the control condition (P Fibromyalgia and Myofascial Pain. Elsevier, Amsterdam, 1993, pp. 311-327.) which predicts increased activity of antagonistic muscle and decreased activity of agonistic muscle during experimental and clinical muscle pain.

Excess glycogen does not resolve high ultimate pH of oxidative muscle.

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England, Eric M; Matarneh, Sulaiman K; Oliver, Emily M; Apaoblaza, Ariel; Scheffler, Tracy L; Shi, Hao; Gerrard, David E

2016-04-01

Skeletal muscle glycogen content can impact the extent of postmortem pH decline. Compared to glycolytic muscles, oxidative muscles contain lower glycogen levels antemortem which may contribute to the higher ultimate pH. In an effort to explore further the participation of glycogen in postmortem metabolism, we postulated that increasing the availability of glycogen would drive additional pH decline in oxidative muscles to equivalent pH values similar to the ultimate pH of glycolytic muscles. Glycolysis and pH declines were compared in porcine longissimus lumborum (glycolytic) and masseter (oxidative) muscles using an in vitro system in the presence of excess glycogen. The ultimate pH of the system containing longissimus lumborum reached a value similar to that observed in intact muscle. The pH decline of the system containing masseter samples stopped prematurely resulting in a higher ultimate pH which was similar to that of intact masseter muscle. To investigate further, we titrated powdered longissimus lumborum and masseter samples in the reaction buffer. As the percentage of glycolytic sample increased, the ultimate pH decreased. These data show that oxidative muscle produces meat with a high ultimate pH regardless of glycogen content and suggest that inherent muscle factors associated with glycolytic muscle control the extent of pH decline in pig muscles. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Statins and muscle pain].

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Yosef, Yoni; Schurr, Daniel; Constantini, Naama

2014-07-01

Statins are used for the prevention and treatment of cardiovascular disease. The treatment is quite safe but not free of side effects, particularly muscle pain. Fear of pain may prevent patients from carrying out exercise or diminish their motivation to return and engage in it, even though both the statins and the exercise have a proven benefit in both treatment and prevention, and a synergistic effect enhances this benefit. Prevalence of muscular pain ranges from 1-30%. Pain usually appears at the beginning of treatment, but can occur even after months and under any of the existing agents. The creatine phosphokinase (CPK) enzyme level may rise, but not necessarily. Increases to exceptional values (10 times the upper normal level) are relatively rare and rhabdomyolysis is extremely rare. The risk increases with age, co-morbidities and especially when taken concurrently with drugs that are metabolized in a similar pathway. Pain usually passes within a month after discontinuing treatment, but may persist for six months or more. Studies have examined the effect of statin therapy on the ability to perform physical activity, but results are inconsistent. The increased rise of CPK was observed under statin therapy, a tendency that increased with age. However, it was not accompanied by an increased incidence of muscle pain or rhabdomyolysis. Considering the above we recommend encouraging patients to exercise. However, patients should be instructed to report new or worsening muscular pains. Discontinuation, lowering dose or replacement should be considered when pain is suspected to be related with treatment.

Mechanisms underlying ectopic persistent tooth-pulp pain following pulpal inflammation.

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Shingo Matsuura

Full Text Available In order to clarify the peripheral mechanisms of ectopic persistent pain in a tooth pulp following pulpal inflammation of an adjacent tooth, masseter muscle activity, phosphorylated extracellular signal-regulated protein kinase (pERK and TRPV1 immunohistochemistries and satellite cell activation using glial fibrillary acidic protein (GFAP immunohistochemistry in the trigeminal ganglion (TG were studied in the rats with molar tooth-pulp inflammation. And, Fluorogold (FG and DiI were also used in a neuronal tracing study to analyze if some TG neurons innervate more than one tooth pulp. Complete Freund's adjuvant (CFA or saline was applied into the upper first molar tooth pulp (M1 in pentobarbital-anesthetized rats, and capsaicin was applied into the upper second molar tooth pulp (M2 on day 3 after the CFA or saline application. Mean EMG activity elicited in the masseter muscle by capsaicin application to M2 was significantly larger in M1 CFA-applied rats compared with M1 vehicle-applied rats. The mean number of pERK-immunoreactive (IR TG cells was significantly larger in M1 CFA-applied rats compared with M1 vehicle-applied rats. Application of the satellite cell inhibitor fluorocitrate (FC into TG caused a significant depression of capsaicin-induced masseter muscle activity and a significant reduction of satellite cell activation. The number of TRPV1-IR TG cells innervating M2 was significantly larger in M1 CFA-applied rats compared with M1 vehicle-applied rats, and that was decreased following FC injection into TG. Furthermore, 6% of TG neurons innervating M1 and/or M2 innervated both M1 and M2. These findings suggest that satellite cell activation following tooth pulp inflammation and innervation of multiple tooth pulps by single TG neurons may be involved in the enhancement of the activity of TG neurons innervating adjacent non-inflamed teeth that also show enhancement of TRPV1 expression in TG neurons, resulting in the ectopic persistent tooth

Influence of botulinum toxin on rabbit jaw muscle activity and anatomy.

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Korfage, J A M; Wang, Jeffrey; Lie, S H J T J; Langenbach, Geerling E J

2012-05-01

Muscles can adapt their fiber properties to accommodate to new conditions. We investigated the extent to which a decrease in muscle activation can cause an adaptation of fiber properties in synergistic and antagonistic jaw muscles. Three months after the injection of botulinum toxin type A in one masseter (anterior or posterior) muscle changes in fiber type composition and fiber cross-sectional areas in jaw muscles were studied at the microscopic level. The injected masseter showed a steep increase in myosin type IIX fibers, whereas fast fibers decreased by about 50% in size. Depending on the injection site, both synergistic and antagonistic muscles showed a significant increase in the size of their fast IIA fibers, sometimes combined with an increased number of IIX fibers. Silencing the activity in the masseter not only causes changes in the fibers of the injected muscle but also leads to changes in other jaw muscles. Copyright © 2012 Wiley Periodicals, Inc.

Does the habitual mastication side impact jaw muscle activity?

Science.gov (United States)

Turcio, Karina Helga Leal; Zuim, Paulo Renato Junqueira; Guiotti, Aimée Maria; Dos Santos, Daniela Micheline; Goiato, Marcelo Coelho; Brandini, Daniela Atili

2016-07-01

To compare electrical activity in the anterior temporal and masseter muscles on the habitual (HMS) and non-habitual mastication side (NHMS), during mastication and in the mandibular postural position. In addition, the increase in electrical activity during mastication was assessed for the HMS and NHMS, analysing both working (WSM) and non-working side during mastication (NWSM). A total of 28 healthy women (18-32 years) participated in the study. They were submitted to Kazazoglu's test to identify the HMS. Bioresearch 'Bio EMG' software and bipolar surface electrodes were used in the exams. The exams were conducted in the postural position and during the unilateral mastication of raisins, on both the HMS and NHMS. The working and non-working side on HMS and NHMS were assessed separately. The obtained data were then statistically analysed with SPSS 20.0, using the Paired Samples Test at a significance level of 95%. The differences in the average EMG values between HMS and NHMS were not statistically significant in the postural position (Temporal p=0.2; Masseter p=0.4) or during mastication (Temporal WSM p=0.8; Temporal NWSM p=0.8; Masseter WSM p=0.6; Masseter NWSM p=0.2). Differences in the increase in electrical activity between the masseter and temporal muscles occurred on the working side, on the HMS and NHMS (p=0.0), but not on the non-working side: HMS (p=0.9) and NHMS (p=0.3). The increase in electrical activity was about 35% higher in the masseter than in the temporal muscle. Mastication side preference does not significantly impact electrical activity of the anterior temporal and masseter muscles during mastication or in postural position. Copyright © 2016. Published by Elsevier Ltd.

Neuropathic Pain-like Alterations in Muscle Nociceptor Function Associated with Vibration-induced Muscle Pain

OpenAIRE

Chen, Xiaojie; Green, Paul G.; Levine, Jon D.

2010-01-01

We recently developed a rodent model of the painful muscle disorders induced by occupational exposure to vibration. In the present study we used this model to evaluate the function of sensory neurons innervating the vibration-exposed gastrocnemius muscle. Activity of 74 vibration-exposed and 40 control nociceptors, with mechanical receptive fields in the gastrocnemius muscle, were recorded. In vibration-exposed rats ~15% of nociceptors demonstrated an intense and long-lasting barrage of actio...

The influence of experimentally induced pain on shoulder muscle activity

DEFF Research Database (Denmark)

Diederichsen, L.P.; Winther, A.; Dyhre-Poulsen, P.

2009-01-01

muscles. EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper......-105A degrees) at a speed of approximately 120A degrees/s, controlled by a metronome. During abduction, electromyographic (EMG) activity was recorded by intramuscular wire electrodes inserted in two deeply located shoulder muscles and by surface-electrodes over six superficially located shoulder...... trapezius and the infraspinatus and an increase in activity of lower trapezius and latissimus dorsi muscles. Following subacromial injection a significantly increased muscle activity was seen in the lower trapezius, the serratus anterior and the latissimus dorsi muscles. In conclusion, this study shows...

Is back pain during childhood or adolescence associated with muscle strength, muscle endurance or aerobic capacity

DEFF Research Database (Denmark)

Lardon, Arnaud; Leboeuf-Yde, Charlotte; Le Scanff, Christine

2015-01-01

BACKGROUND: Back pain is a common condition during childhood and adolescence. The causes of back pain are largely unknown but it seems plausible that some physical factors such as back muscle strength, back muscle endurance and aerobic capacity may play a role in its development, in particular...... aerobic capacity and back pain is not clear. CONCLUSIONS: High back muscle endurance in extension appears protective of back pain in youngsters, but the roles of high back muscle strength in extension and aerobic capacity are less clear....

Mucosal versus muscle pain sensitivity in provoked vestibulodynia

Directory of Open Access Journals (Sweden)

Witzeman K

2015-08-01

Full Text Available Kathryn Witzeman,1 Ruby HN Nguyen,2 Alisa Eanes,3 Sawsan As-Sanie,4 Denniz Zolnoun51Department of Obstetrics and Gynecology, Denver Health Medical Center, Denver, CO, 2Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, 3Pelvic Pain Research Unit, Division of Advanced Laparoscopy and Pelvic Pain, Department of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, NC, 4Department of Obstetrics and Gynecology, Division of Minimally Invasive Gynecologic Surgery, University of Michigan, Ann Arbor, MI, 5Department of Obstetrics and Gynecology and Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, NC, USABackground: An estimated 8.3%–16% of women experience vulvovaginal discomfort during their lifetime. Frequently these patients report provoked pain on contact or with attempted intercourse, commonly referred to as provoked vestibulodynia (PVD. Despite the burden of this condition, little is known about its potential etiologies including pelvic floor muscular dysfunction and mucosal components. This knowledge would be beneficial in developing targeted therapies including physical therapy.Objective: To explore the relative contribution of mucosal versus muscle pain sensitivity on pain report from intercourse among women with PVD.Design: In this proof of concept study, 54 women with PVD underwent a structured examination assessing mucosal and pelvic muscle sensitivity.Methods: We examined three mucosal sites in the upper and lower vestibule. Patients were asked to rate their pain on cotton swab palpation of the mucosa using a 10-point visual analog scale. Muscle pain was assessed using transvaginal application of pressure on right and left puborectalis, and the perineal muscle complex. The Gracely pain scale (0–100 was used to assess the severity of pain with intercourse, with women rating the lowest, average, and highest pain levels; a 100 rating the

Myofascial Pain Dysfunction Syndrome (MPDS

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Hamed Mortazavi

2010-10-01

Full Text Available Introduction: Myofascial Pain Dysfunction Syndrome (MPDS is one of the most important causes of the orofacial pain. The main purpose of this study was to evaluate 40 related variables in this regard. Materials and Methods: Thirty nine patients with MPDS were evaluated in this study. Different factors including age, gender, occupation, marital status, sensitivity of masticatory muscles, maximum opening of the mouth, deviation, deflection, involvement of temporomandibular joint, habit, parafunction, malocclusion, neck pain, headache, earache and history of jaw involvement, etc were analyzed in this  evaluation. Results: In our study, 39 patients (32 females and 7 males, 20-40 years old, with the average age of 35 ± 13.32 years were studied. 51% were housewives and 74.4% were married. The most common involvements were Clicking (74.4%, pain in temporomandibular joint (54%, headache (46.2%, earache (41%, neck-pain (35.9%, trouble in the mouth opening (71.8%, malocclusion Class I (74.4%, cross bite and deep bite (25%, clenching (64.1% and involvement of masseter and lateral pterygoid muscle (84%. Conclusion: Since MPDS consists of variable symptoms, it might be very difficult to provide any definite diagnosis and treatment. Therefore the more the specialists extend their knowledge and information about this disorder, the more they will make the best decision in this regard.

Neck muscle function in violinists/violists with and without neck pain.

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Steinmetz, Anke; Claus, Andrew; Hodges, Paul W; Jull, Gwendolen A

2016-04-01

Neck pain is associated with changes in neuromuscular control of cervical muscles. Violin and viola playing requires good function of the flexor muscles to stabilize the instrument. This study investigated the flexor muscle behaviour in violin/viola players with and without neck pain using the craniocervical flexion test (CCFT). In total, 12 violin/viola players with neck pain, 21 violin/viola players without neck pain in the preceding 12 weeks and 21 pain-free non-musicians were included. Activity of the sternocleidomastoid muscles (SCM) was measured with surface electromyography (EMG) during the CCFT. Violin/viola players with neck pain displayed greater normalised SCM EMG amplitudes during CCFT than the pain-free musicians and non-musicians (P neck pain in violinists/violists is associated with altered behaviour of the superficial neck flexor muscles consistent with neck pain, despite the specific use of the deep and superficial neck flexors during violin playing.

[Asymmetric hypertrophy of the masticatory muscles].

Science.gov (United States)

Arzul, L; Corre, P; Khonsari, R H; Mercier, J-M; Piot, B

2012-06-01

Hypertrophy of the masticatory muscles most commonly affects the masseter. Less common cases of isolated or associated temporalis hypertrophy are also reported. Parafunctional habits, and more precisely bruxism, can favor the onset of the hypertrophy. This condition is generally idiopathic and can require both medical and/or surgical management. A 29-year-old patient was referred to our department for an asymmetric swelling of the masticatory muscles. Physical examination revealed a bilateral hypertrophy of the masticatory muscles, predominantly affecting the right temporalis and the left masseter. Major bruxism was assessed by premature dental wearing. The additional examinations confirmed the isolated muscle hypertrophy. Benign asymmetric hypertrophy of the masticatory muscles promoted by bruxism was diagnosed. Treatment with injections of type A botulinum toxin was conducted in association with a splint and relaxation. Its effectiveness has been observed at six months. Few cases of unilateral or bilateral temporalis hypertrophy have been reported, added to the more common isolated masseter muscles hypertrophy. The diagnosis requires to rule out secondary hypertrophies and tumors using Magnetic Resonance Imaging. The condition is thought to be favoured by parafunctional habits such as bruxism. The conservative treatment consists in reducing the volume of the masticatory muscles using intramuscular injections of type A botulinum toxin. Other potential conservative treatments are wearing splints and muscle relaxant drugs. Surgical procedures aiming to reduce the muscle volume and/or the bone volume (mandibular gonioplasty) can be proposed. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Experimental quadriceps muscle pain impairs knee joint control during walking

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Henriksen, Marius; Alkjaer, Tine; Lund, Hans

2007-01-01

Pain is a cardinal symptom in musculoskeletal diseases involving the knee joint, and aberrant movement patterns and motor control strategies are often present in these patients. However, the underlying neuromuscular mechanisms linking pain to movement and motor control are unclear. To investigate...... the functional significance of muscle pain on knee joint control during walking, three-dimensional gait analyses were performed before, during, and after experimentally induced muscle pain by means of intramuscular injections of hypertonic saline (5.8%) into vastus medialis (VM) muscle of 20 healthy subjects....... Isotonic saline (0.9%) was used as control. Surface electromyography (EMG) recordings of VM, vastus lateralis (VL), biceps femoris, and semitendinosus muscles were synchronized with the gait analyses. During experimental muscle pain, the loading response phase peak knee extensor moments were attenuated...

Muscle function and origin of pain in fibromyalgia

DEFF Research Database (Denmark)

Bennett, R M; Jacobsen, Søren

1994-01-01

It may be concluded that both peripheral and central mechanisms may operate in the pathophysiology of both impaired muscle function and pain in FM. These mechanisms may in part be attributable to physical deconditioning and disuse of muscle secondary to the characteristic pain and fatigue so ofte...

Masticatory muscle pain: Causes, consequences, and diagnosis

NARCIS (Netherlands)

Koutris, M.

2013-01-01

Masticatory muscle pain is known as myogenous temporomandibular disorder (TMD) pain. It has a prevalence of approximately 10% in the general population and affects women more than men. It is usually characterized by a dull, aching pain, which aggravates on function. The etiology of TMD pain is still

Efficacy of photobiomodulation therapy on masseter thickness and oral health-related quality of life in children with spastic cerebral palsy.

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Santos, Maria Teresa Botti Rodrigues; Nascimento, Karla Santos; Carazzato, Simone; Barros, Alina Oliveira; Mendes, Fausto Medeiros; Diniz, Michele Baffi

2017-08-01

The study aimed to evaluate the efficacy of photobiomodulation therapy (PBMT) on bilateral masseter muscle thickness and amplitude of mouth opening in children with spastic cerebral palsy (CP), and the impact on their oral health-related quality of life (OHRQOL). Three groups were included: experimental CP group (EG: n = 26 with oral complaints), positive control CP group (PCG: n = 26 without complaints), and negative control group (NCG: n = 26 without CP). In the EG, the masseter muscles on both sides were irradiated with an infrared low-level Ga-Al-As laser (λ = 808 ± 3 nm, 120 mW) using a 3 J/cm 2 energy dose per site, with a 20 s exposure time per site (spot area: 4 mm 2 ; irradiance: 3 W/cm 2 ; energy delivery per point: 2.4 J) six times over six consecutive weeks. Masseter thickness, assessed through ultrasonography, and the amplitude of mouth opening were measured in the EG before and after six applications of PBMT and once in the PCG and NCG. The Parental-Caregiver Perception Questionnaire (P-CPQ) was used to evaluate OHRQOL. ANOVA, chi-square, t tests, and multilevel linear regression were used for statistical analysis. In the EG, the study results revealed average increments of 0.77 (0.08) millimeter in masseter thickness (P < 0.05) and 7.39 (0.58) millimeter for mouth opening (P < 0.05) and reduction in all P-CPQ domains (P < 0.001), except for social well-being. The six applications of PBMT increased masseter thickness and mouth opening amplitude and reduced the impact of spastic CP on OHRQOL.

Influence of Polymorphisms in the HTR3A and HTR3B Genes on Experimental Pain and the Effect of the 5-HT3 Antagonist Granisetron.

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Louca Jounger, Sofia; Christidis, Nikolaos; Hedenberg-Magnusson, Britt; List, Thomas; Svensson, Peter; Schalling, Martin; Ernberg, Malin

2016-01-01

The aim of this study was to investigate experimentally if 5-HT3 single nucleotide polymorphisms (SNP) contribute to pain perception and efficacy of the 5-HT3-antagonist granisetron and sex differences. Sixty healthy participants were genotyped regarding HTR3A (rs1062613) and HTR3B (rs1176744). First, pain was induced by bilateral hypertonic saline injections (HS, 5.5%, 0.2 mL) into the masseter muscles. Thirty min later the masseter muscle on one side was pretreated with 0.5 mL granisetron (1 mg/mL) and on the other side with 0.5 mL placebo (isotonic saline) followed by another HS injection (0.2 mL). Pain intensity, pain duration, pain area and pressure pain thresholds (PPTs) were assessed after each injection. HS evoked moderate pain, with higher intensity in the women (P = 0.023), but had no effect on PPTs. None of the SNPs influenced any pain variable in general, but compared to men, the pain area was larger in women carrying the C/C (HTR3A) (P = 0.015) and pain intensity higher in women with the A/C alleles (HTR3B) (P = 0.019). Pre-treatment with granisetron reduced pain intensity, duration and area to a lesser degree in women (P granisetron. Women carrying the C/T & T/T (HTR3A) genotype had less reduction of pain intensity (P = 0.041) and area (P = 0.005), and women with the C/C genotype (HTR3B) had less reduction of pain intensity (P = 0.030), duration (P = 0.030) and area compared to men (P = 0.017). In conclusion, SNPs did not influence experimental muscle pain or the effect of granisetron on pain variables in general, but there were some sex differences in pain variables that seem to be influenced by genotypes. However, due to the small sample size further research is needed before any firm conclusions can be drawn.

Influence of Polymorphisms in the HTR3A and HTR3B Genes on Experimental Pain and the Effect of the 5-HT3 Antagonist Granisetron.

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Sofia Louca Jounger

Full Text Available The aim of this study was to investigate experimentally if 5-HT3 single nucleotide polymorphisms (SNP contribute to pain perception and efficacy of the 5-HT3-antagonist granisetron and sex differences. Sixty healthy participants were genotyped regarding HTR3A (rs1062613 and HTR3B (rs1176744. First, pain was induced by bilateral hypertonic saline injections (HS, 5.5%, 0.2 mL into the masseter muscles. Thirty min later the masseter muscle on one side was pretreated with 0.5 mL granisetron (1 mg/mL and on the other side with 0.5 mL placebo (isotonic saline followed by another HS injection (0.2 mL. Pain intensity, pain duration, pain area and pressure pain thresholds (PPTs were assessed after each injection. HS evoked moderate pain, with higher intensity in the women (P = 0.023, but had no effect on PPTs. None of the SNPs influenced any pain variable in general, but compared to men, the pain area was larger in women carrying the C/C (HTR3A (P = 0.015 and pain intensity higher in women with the A/C alleles (HTR3B (P = 0.019. Pre-treatment with granisetron reduced pain intensity, duration and area to a lesser degree in women (P < 0.05, but the SNPs did not in general influence the efficacy of granisetron. Women carrying the C/T & T/T (HTR3A genotype had less reduction of pain intensity (P = 0.041 and area (P = 0.005, and women with the C/C genotype (HTR3B had less reduction of pain intensity (P = 0.030, duration (P = 0.030 and area compared to men (P = 0.017. In conclusion, SNPs did not influence experimental muscle pain or the effect of granisetron on pain variables in general, but there were some sex differences in pain variables that seem to be influenced by genotypes. However, due to the small sample size further research is needed before any firm conclusions can be drawn.

Oral cavity reconstruction with the masseter flap

NARCIS (Netherlands)

Mahieu, R.; Russo, S.; Gualtieri, T.; Colletti, G.; Deganello, A.

The purpose of this report is to highlight how an unusual, outdated, unpopular and overlooked reconstructive method such as the masseter flap can be a reliable, straightforward and effective solution for oral reconstruction in selected cases. We report the transposition of the masseter crossover

Masticatory muscle sleep background electromyographic activity is elevated in myofascial temporomandibular disorder patients.

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Raphael, K G; Janal, M N; Sirois, D A; Dubrovsky, B; Wigren, P E; Klausner, J J; Krieger, A C; Lavigne, G J

2013-12-01

Despite theoretical speculation and strong clinical belief, recent research using laboratory polysomnographic (PSG) recording has provided new evidence that frequency of sleep bruxism (SB) masseter muscle events, including grinding or clenching of the teeth during sleep, is not increased for women with chronic myofascial temporomandibular disorder (TMD). The current case-control study compares a large sample of women suffering from chronic myofascial TMD (n = 124) with a demographically matched control group without TMD (n = 46) on sleep background electromyography (EMG) during a laboratory PSG study. Background EMG activity was measured as EMG root mean square (RMS) from the right masseter muscle after lights out. Sleep background EMG activity was defined as EMG RMS remaining after activity attributable to SB, other orofacial activity, other oromotor activity and movement artefacts were removed. Results indicated that median background EMG during these non-SB event periods was significantly higher (P cases exceeding control activity. Moreover, for TMD cases, background EMG was positively associated and SB event-related EMG was negatively associated with pain intensity ratings (0-10 numerical scale) on post-sleep waking. These data provide the foundation for a new focus on small, but persistent, elevations in sleep EMG activity over the course of the night as a mechanism of pain induction or maintenance. © 2013 John Wiley & Sons Ltd.

Paraspinal muscle hypotrophy and chronic discogenic low back pain

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Truszczyńska-Baszak Aleksandra

2018-01-01

Full Text Available Study aim: Low back pain is accompanied by deconditioning of trunk muscles due to pain limiting patients’ physical activity, but so far it has not been explained whether the changes in the structure of muscles are the cause of disc disease or its result. The aim of the study was to analyze the prevalence of segmental paraspinal muscle hypotrophy in patients with chronic low back pain and sciatica. Material and methods: The study involved magnetic resonance imaging (MRI of 40 patients: 20 women and 20 men aged from 30 to 47, mean 39.51 ± 3.73 years, with single level disc extrusion at L4-L5. The entire cross-sectional area of the par­aspinal muscles, the adipose tissue area in the paraspinal muscles and the extensor muscle tissue area at the level of L4-L5 were measured and compared with the healthy L3-L4 level. T2-weighted axial slices were used to facilitate distinguishing between the muscle and the fat tissue. Results: Fat tissue ingrowth and paravertebral muscle tissue hypotrophy at the disc extrusion level were highly statistically significant (p < 0.001 compared to the healthy level. Conclusions: 1. Ingrowth of the adipose tissue into the muscle tissue occurs only at the level of disc extrusion. 2. It seems rea­sonable to introduce strengthening exercises after the resolution of pain in order to rebuild the muscles of the spine.

The relationships among jaw-muscle fiber architecture, jaw morphology, and feeding behavior in extant apes and modern humans.

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Taylor, Andrea B; Vinyard, Christopher J

2013-05-01

The jaw-closing muscles are responsible for generating many of the forces and movements associated with feeding. Muscle physiologic cross-sectional area (PCSA) and fiber length are two architectural parameters that heavily influence muscle function. While there have been numerous comparative studies of hominoid and hominin craniodental and mandibular morphology, little is known about hominoid jaw-muscle fiber architecture. We present novel data on masseter and temporalis internal muscle architecture for small- and large-bodied hominoids. Hominoid scaling patterns are evaluated and compared with representative New- (Cebus) and Old-World (Macaca) monkeys. Variation in hominoid jaw-muscle fiber architecture is related to both absolute size and allometry. PCSAs scale close to isometry relative to jaw length in anthropoids, but likely with positive allometry in hominoids. Thus, large-bodied apes may be capable of generating both absolutely and relatively greater muscle forces compared with smaller-bodied apes and monkeys. Compared with extant apes, modern humans exhibit a reduction in masseter PCSA relative to condyle-M1 length but retain relatively long fibers, suggesting humans may have sacrificed relative masseter muscle force during chewing without appreciably altering muscle excursion/contraction velocity. Lastly, craniometric estimates of PCSAs underestimate hominoid masseter and temporalis PCSAs by more than 50% in gorillas, and overestimate masseter PCSA by as much as 30% in humans. These findings underscore the difficulty of accurately estimating jaw-muscle fiber architecture from craniometric measures and suggest models of fossil hominin and hominoid bite forces will be improved by incorporating architectural data in estimating jaw-muscle forces. Copyright © 2013 Wiley Periodicals, Inc.

Kinesiophobia, Pain, Muscle Functions, and Functional Performances among Older Persons with Low Back Pain

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Nor Azizah Ishak

2017-01-01

Full Text Available Objectives. This study aims (1 to determine the association between kinesiophobia and pain, muscle functions, and functional performances and (2 to determine whether kinesiophobia predicts pain, muscle functions, and functional performance among older persons with low back pain (LBP. Methods. This is a correlational study, involving 63 institutionalized older persons (age = 70.98±7.90 years diagnosed with LBP. Anthropometric characteristics (BMI and functional performances (lower limb function, balance and mobility, and hand grip strength were measured. Muscle strength (abdominal and back muscle strength was assessed using the Baseline® Mechanical Push/Pull Dynamometer, while muscle control (transverse abdominus and multifidus was measured by using the Pressure Biofeedback Unit. The pain intensity and the level of kinesiophobia were measured using Numerical Rating Scale and Tampa Scale of Kinesiophobia, respectively. Data were analyzed using Pearson’s correlation coefficients and multivariate linear regressions. Results. No significant correlations were found between kinesiophobia and pain and muscle functions (all p>0.05. Kinesiophobia was significantly correlated with mobility and balance (p=0.038, r=0.263. Regressions analysis showed that kinesiophobia was a significant predictor of mobility and balance (p=0.038. Conclusion. We can conclude that kinesiophobia predicted mobility and balance in older persons with LBP. Kinesiophobia should be continuously assessed in clinical settings to recognize the obstacles that may affect patient’s compliance towards a rehabilitation program in older persons with LBP.

Comparative jaw muscle anatomy in kangaroos, wallabies, and rat-kangaroos (marsupialia: macropodoidea).

Science.gov (United States)

Warburton, Natalie Marina

2009-06-01

The jaw muscles were studied in seven genera of macropodoid marsupials with diets ranging from mainly fungi in Potorous to grass in Macropus. Relative size, attachments, and lamination within the jaw adductor muscles varied between macropodoid species. Among macropodine species, the jaw adductor muscle proportions vary with feeding type. The relative mass of the masseter is roughly consistent, but grazers and mixed-feeders (Macropus and Lagostrophus) had relatively larger medial pterygoids and smaller temporalis muscles than the browsers (Dendrolagus, Dorcopsulus, and Setonix). Grazing macropods show similar jaw muscle proportions to "ungulate-grinding" type placental mammals. The internal architecture of the jaw muscles also varies between grazing and browsing macropods, most significantly, the anatomy of the medial pterygoid muscle. Potoroines have distinctly different jaw muscle proportions to macropodines. The masseter muscle group, in particular, the superficial masseter is enlarged, while the temporalis group is relatively reduced. Lagostrophus fasciatus is anatomically distinct from other macropods with respect to its masticatory muscle anatomy, including enlarged superficial medial pterygoid and deep temporalis muscles, an anteriorly inflected masseteric process, and the shape of the mandibular condyle. The enlarged triangular pterygoid process of the sphenoid bone, in particular, is distinctive of Lagsotrophus. (c) 2009 Wiley-Liss, Inc.

Repeated Muscle Injury as a Presumptive Trigger for Chronic Masticatory Muscle Pain

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Dean Dessem

2011-01-01

Full Text Available skeletal muscles sustain a significant loss of maximal contractile force after injury, but terminally damaged fibers can eventually be replaced by the growth of new muscle (regeneration, with full restoration of contractile force over time. After a second injury, limb muscles exhibit a smaller reduction in maximal force and reduced inflammation compared with that after the initial injury (i.e., repeated bout effect. In contrast, masticatory muscles exhibit diminished regeneration and persistent fibrosis, after a single injury; following a second injury, plasma extravasation is greater than after a single injury and maximal force is decreased more than after the initial injury. Thus, masticatory muscles do not exhibit a repeated bout effect and are instead increasingly damaged by repeated injury. We propose that the impaired ability of masticatory muscles to regenerate contributes to chronic muscle pain by leading to an accumulation of tissue damage, fibrosis, and a persistent elevation and prolonged membrane translocation of nociceptive channels such as P2X3 as well as enhanced expression of neuropeptides including CGRP within primary afferent neurons. These transformations prime primary afferent neurons for enhanced responsiveness upon subsequent injury thus triggering and/or exacerbating chronic muscle pain.

Muscle-tendon-related pain in 100 patients with hip dysplasia: prevalence and associations with self-reported hip disability and muscle strength

DEFF Research Database (Denmark)

Jacobsen, Julie Sandell; Hølmich, Per; Thorborg, Kristian

2018-01-01

The primary aim was to identify muscle-tendon-related pain in 100 patients with hip dysplasia. The secondary aim was to test whether muscle-tendon-related pain is associated with self-reported hip disability and muscle strength in patient with hip dysplasia. One hundred patients (17 men......-tendon-related pain and hip extension a significant inverse linear association between muscle-tendon-related pain and muscle strength was found ranging from -0.11 to - 0.12 Nm/kg in the adjusted analysis (P hip dysplasia with a high prevalence......) with a mean age of 29 years (SD 9) were included. Clinical entity approach was carried out to identify muscle-tendon-related pain. Associations between muscle-tendon-related pain and self-reported hip disability and muscle strength were tested with multiple regression analysis, including adjustments for age...

Digital dissection of the masticatory muscles of the naked mole-rat, Heterocephalus glaber (Mammalia, Rodentia

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Philip G. Cox

2014-06-01

Full Text Available The naked mole-rat, Heterocephalus glaber, of the family Bathyergidae is a subterranean rodent that feeds on underground roots and tubers and digs extensive tunnel systems with its incisors. It is a highly unusual mammal with regard to its social structure, longevity, pain insensitivity and cancer resistance, all of which have made it the subject of a great deal of research in recent years. Yet, much of the basic anatomy of this species remains undocumented. In this paper, we describe the morphology of the jaw-closing musculature of the naked mole-rat, as revealed by contrast-enhanced micro-computed tomography. This technique uses an iodine stain to enable the imaging of soft tissues with microCT. The iodine-enhanced scans were used to create 3D reconstructions of the naked mole-rat masticatory muscles from which muscle masses were calculated. The jaw-closing musculature of Heterocephalus glaber is relatively very large compared to other rodents and is dominated by the superficial masseter, the deep masseter and the temporalis. The temporalis in particular is large for a rodent, covering the entirety of the braincase and much of the rear part of the orbit. The morphology of the masseter complex described here differs from two other published descriptions of bathyergid masticatory muscles, but is more similar to the arrangement seen in other rodent families. The zygomaticomandibularis (ZM muscle does not protrude through the infraorbital foramen on to the rostrum and thus the naked mole-rat should be considered protrogomorphous rather than hystricomorphous, and the morphology is consistent with secondarily lost hystricomorphy as has been previously suggested for Bathyergidae. Overall, the morphology of the masticatory musculature indicates a species with a high bite force and a wide gape–both important adaptations for a life dominated by digging with the incisors.

Decreased thickness of the lower trapezius muscle in patients with unilateral neck pain.

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Uthaikhup, Sureeporn; Pensri, Chalomjai; Kawsoiy, Kanokon

2016-09-01

Thickness of the lower trapezius muscle in patients with neck pain has not been established. We examined the thickness of the lower trapezius muscle in patients with and without unilateral neck pain. Twenty women with unilateral (right) neck pain and 20 matched controls participated in the study. Thickness of the lower trapezius muscles was measured bilaterally at rest (0 ° and 120 ° of shoulder abduction) and during contraction (120 ° of shoulder abduction) using ultrasound imaging. The neck pain group had smaller thickness of the lower trapezius muscle on the painful side compared with controls both at rest and during contraction (P  0.05). Patients with neck pain had smaller thickness of the lower trapezius muscle on the painful side compared with healthy controls. Muscle Nerve 54: 439-443, 2016. © 2015 Wiley Periodicals, Inc.

Muscle-tendon-related pain in 100 patients with hip dysplasia: prevalence and associations with self-reported hip disability and muscle strength

DEFF Research Database (Denmark)

Jacobsen, Julie Sandell; Hölmich, Per; Thorborg, Kristian

2017-01-01

The primary aim was to identify muscle-tendon-related pain in 100 patients with hip dysplasia. The secondary aim was to test whether muscle-tendon-related pain is associated with self-reported hip disability and muscle strength in patient with hip dysplasia. One hundred patients (17 men......-tendon-related pain and hip extension a significant inverse linear association between muscletendon- related pain and muscle strength was found ranging from 0.11 to0.12 Nm/kg in the adjusted analysis (Phip dysplasia with a high prevalence......) with a mean age of 29 years (SD 9) were included. Clinical entity approach was carried out to identify muscle-tendon-related pain. Associations between muscle-tendon-related pain and self-reported hip disability and muscle strength were tested with multiple regression analysis, including adjustments for age...

Experimental tooth clenching. A model for studying mechanisms of muscle pain.

Science.gov (United States)

Dawson, Andreas

2013-01-01

) participated in two sessions at a minimum interval of 1 wk. Microdialysis was done to collect 5-HT, glutamate, pyruvate, and lactate and to measure masseter muscle blood flow. Two hours after the start of microdialysis, participants were randomized to a 20-min repetitive experimental tooth clenching task (50% of MVCF) or a control session (no clenching). Pain intensity was measured throughout the experiment. Substance levels and blood flow were unaltered at all time points between sessions, and between genders in each session. Pain intensity was significantly higher after clenching in the clenching session compared to the same time point in the control session. In (IV), 15 patients with M-TMD and 15 healthy controls participated in one session and the methodology described above was used. M-TMD patients had significantly higher levels of 5-HT and significantly lower blood flows than healthy controls. No significant differences for any substance at any time point were observed between groups. Time and group had significant main effects on pain intensity. Qu-ATEBS, the 7-item evidence-based quality assessment tool, is reliable, exhibits face-validity, and has excellent discriminative validity. Tooth clenching was associated with pain, fatigue, and short-lasting mechanical hyperalgesia, but not with proprioceptive allodynia. It seems that tooth clenching is not directly related to delayed onset muscle soreness. In healthy subjects and in patients with M-TMD, levels of 5-HT, glutamate, pyruvate, and lactate were unaltered after tooth clenching. But 5-HT levels were significantly higher and blood flows significantly lower in M-TMD patients than in healthy controls at all time points. These two factors may facilitate the release, and enhance the effects, of other algesic substances that may cause pain.

Myoelectric manifestations of jaw elevator muscle fatigue and recovery in healthy and TMD subjects.

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Castroflorio, T; Falla, D; Tartaglia, G M; Sforza, C; Deregibus, A

2012-09-01

The effects of muscle pain and fatigue on the control of jaw elevator muscles are not well known. Furthermore, the myoelectric manifestations of fatigue and recovery from fatigue in the masticatory muscles are not reported in literature. The main aims of this study were (i) to evaluate the possible use of surface electromyography (sEMG) as an objective measure of fatigue of the jaw elevator muscles, (ii) to compare the myoelectric manifestations of fatigue in the temporalis anterior and masseter muscles bilaterally, (iii) to assess recovery of the investigated muscles after an endurance test and (iv) to compare fatigue and recovery of the jaw elevator muscles in healthy subjects and patients with muscle-related temporomandibular disorders (TMD). The study was performed on twenty healthy volunteers and eighteen patients with muscle-related TMD. An intra-oral compressive-force sensor was used to measure the voluntary contraction forces close to the intercuspal position and to provide visual feedback of submaximal forces to the subject. Surface EMG signals were recorded with linear electrode arrays during isometric contractions at 20%, 40%, 60% and 80% of the maximum voluntary contraction force, during an endurance test and during the recovery phase. The results showed that (i) the slope of the mean power spectral frequency (MNF) and the initial average rectified value (ARV) could be used to monitor fatigue of the jaw elevators, (ii) the temporalis anterior and masseter muscle show the same myoelectric manifestations of fatigue and recovery and (iii) the initial values of MNF and ARV were lower in patients with muscle-related TMD. The assessment of myoelectric manifestations of fatigue in the masticatory muscles may assist in the clinical assessment of TMDs. © 2012 Blackwell Publishing Ltd.

Effect of two contrasting types of physical exercise on chronic neck muscle pain

DEFF Research Database (Denmark)

Andersen, Lars L; Kjaer, Michael; Søgaard, Karen

2008-01-01

trial and recruited subjects from 7 workplaces characterized by monotonous jobs (e.g., computer-intensive work). Forty-eight employed women with chronic neck muscle pain (defined as a clinical diagnosis of trapezius myalgia) were randomly assigned to 10 weeks of specific strength training locally......OBJECTIVE: The prevalence of neck muscle pain has steadily increased and especially pain from the descending part of the trapezius muscle has been associated with monotonous work tasks such as computer work. Physical exercise is generally recommended as treatment, but it is unclear which type...... of training is most effective. Our objective was to determine the effectiveness of specific strength training of the painful muscle versus general fitness training without direct involvement of the painful muscle (leg bicycling) on work-related neck muscle pain. METHODS: We conducted a randomized controlled...

Effect of two contrasting types of physical exercise on chronic neck muscle pain

DEFF Research Database (Denmark)

Andersen, L.L.; Kjær, Michael; Søgaard, Kirsten

2008-01-01

trial and recruited subjects from 7 workplaces characterized by monotonous jobs (e.g., computer-intensive work). Forty-eight employed women with chronic neck muscle pain (defined as a clinical diagnosis of trapezius myalgia) were randomly assigned to 10 weeks of specific strength training locally......Objective. The prevalence of neck muscle pain has steadily increased and especially pain from the descending part of the trapezius muscle has been associated with monotonous work tasks such as computer work. Physical exercise is generally recommended as treatment, but it is unclear which type...... of training is most effective. Our objective was to determine the effectiveness of specific strength training of the painful muscle versus general fitness training without direct involvement of the painful muscle (leg bicycling) on work-related neck muscle pain. Methods. We conducted a randomized controlled...

Structure and function of masticatory muscles in a case of muscular dystrophy

DEFF Research Database (Denmark)

Bakke, M; Kirkeby, S; Jensen, B L

1990-01-01

Histologic examination of muscle biopsies and functional examination comprising electromyography and force measurements in a 19-yr-old boy with muscular dystrophy showed different wasting patterns of mandibular elevator and depressor muscles. Pronounced histopathologic changes were present...... depressor strength corresponded more to reference values. This difference of muscular wasting might be caused by protective enzymes in the digastric muscle and/or functionally induced damage of the masseter. As affection from muscular dystrophy may vary greatly between the masticatory muscles, structural...... in the masseter muscle, whereas pathologic findings in the anterior digastric muscle were limited to increased number of cells in slightly enlarged interfiber connective tissue. The masticatory pattern was distorted, and strength of mandibular elevator muscles was less than one third of the norm, whereas...

A study of the masticatory muscles morphology and function on asymmetric prognathism

International Nuclear Information System (INIS)

Kondoh, Hirotoshi

1991-01-01

Each case was measured to analyze the cross sectional area of muscle and mandibular malposition amount using Computed Tomography (CT) photos and P-A cephalogram. At the same time, the relation of morphology and function between the cross sectional area of muscle and mandibular malposition amount was analyzed to examine the function of masseter using electromyography. To determine the relation between morphology and function of masseter in asymmetric prognathism, 23 cases were chosen for the study from among 11 male and 12 female patients who were diagnosed as asymmetric prognathism. In asymmetric prognathism, both morphology and function in the mandibular malposition side were recognized to be larger than that in the cross sectional area of muscle side, on the examination of the cross sectional area of muscle and the activity of masseter. A highly significant and positive correlation was recognized in the left and right difference between the masseteric and medial pterygoid section areas and the CT mandibular malposition amount which were examined by the CT photos. In the left and right difference between the masseteric and medial pterygoid section areas and in the left and right difference of the activity of masseter, there was also a highly positive and significant correlation. (author) 58 refs

Induction and modulation of referred muscle pain in humans

DEFF Research Database (Denmark)

Laursen, René Johannes

correlated to pain intensity, and LP and RP thresholds were reproducible within and between sessions. Experimentally (electrical stimulation and infusion of hypertonic saline) induced muscle pain seems to be mediated by myelinated and unmyelinated afferents and the peripheral component of RP by myelinated...... afferents. Furthermore, cutaneous anesthesia of the RP area resulted in a reduction of RP intensity of 22%, while a complete nerve block of afferents from the RP area resulted in a 40% reduction. In summary, observations from the presented experiments suggest that elicitation of referred muscle pain...... is depending on and correlated to local muscle pain. Peripheral input from the RP area is involved, but is not a necessary condition for RP to appear. The present studies as well as others suggest that central hyperexcitability is involved in the generation of RP, but further investigations on mechanisms of RP...

Neck movement and muscle activity characteristics in female office workers with neck pain.

Science.gov (United States)

Johnston, V; Jull, G; Souvlis, T; Jimmieson, N L

2008-03-01

Cross-sectional study. To explore aspects of cervical musculoskeletal function in female office workers with neck pain. Evidence of physical characteristics that differentiate computer workers with and without neck pain is sparse. Patients with chronic neck pain demonstrate reduced motion and altered patterns of muscle control in the cervical flexor and upper trapezius (UT) muscles during specific tasks. Understanding cervical musculoskeletal function in office workers will better direct intervention and prevention strategies. Measures included neck range of motion; superficial neck flexor muscle activity during a clinical test, the craniocervical flexion test; and a motor task, a unilateral muscle coordination task, to assess the activity of both the anterior and posterior neck muscles. Office workers with and without neck pain were formed into 3 groups based on their scores on the Neck Disability Index. Nonworking women without neck pain formed the control group. Surface electromyographic activity was recorded bilaterally from the sternocleidomastoid, anterior scalene (AS), cervical extensor (CE) and UT muscles. Workers with neck pain had reduced rotation range and increased activity of the superficial cervical flexors during the craniocervical flexion test. During the coordination task, workers with pain demonstrated greater activity in the CE muscles bilaterally. On completion of the task, the UT and dominant CE and AS muscles demonstrated an inability to relax in workers with pain. In general, there was a linear relationship between the workers' self-reported levels of pain and disability and the movement and muscle changes. These results are consistent with those found in other cervical musculoskeletal disorders and may represent an altered muscle recruitment strategy to stabilize the head and neck. An exercise program including motor reeducation may assist in the management of neck pain in office workers.

Reorganized trunk muscle activity during multidirectional floor perturbations after experimental low back pain

DEFF Research Database (Denmark)

Larsen, Lars Henrik; Hirata, Rogerio Pessoto; Graven-Nielsen, Thomas

2016-01-01

Low back pain changes the trunk muscle activity after external perturbations but the relationship between pain intensities and distributions and their effect on the trunk muscle activity remains unclear. The effects of unilateral and bilateral experimental low back pain on trunk muscle activity w...

The Associations between Pain Sensitivity and Knee Muscle Strength in Healthy Volunteers

DEFF Research Database (Denmark)

Henriksen, Marius; Klokker, Louise; Bartholdy, Cecilie

2013-01-01

lateralis, deltoid, and infrapatellar fat pad. Quadriceps and hamstring muscle strength was assessed isometrically at 60-degree knee flexion using a dynamometer. Associations between pain sensitivity and muscle strength were investigated using multiple regressions including age, gender, and body mass index...... as covariates. Results. Knee extension strength was associated with computer-controlled PPT on the vastus lateralis muscle. Computer-controlled PPTs were significantly correlated between sites (r > 0.72) and with cuff PPT (r > 0.4). Saline induced pain intensity and duration were correlated between sites (r > 0......Objectives. To investigate associations between muscle strength and pain sensitivity among healthy volunteers and associations between different pain sensitivity measures. Methods. Twenty-eight healthy volunteers (21 females) participated. Pressure pain thresholds (PPTs) were obtained from 1...

Impact of Functional Appliances on Muscle Activity: A Surface Electromyography Study in Children

Science.gov (United States)

Woźniak, Krzysztof; Piątkowska, Dagmara; Szyszka-Sommerfeld, Liliana; Buczkowska-Radlińska, Jadwiga

2015-01-01

Background Electromyography (EMG) is the most objective tool for assessing changes in the electrical activity of the masticatory muscles. The purpose of the study was to evaluate the tone of the masseter and anterior temporalis muscles in growing children before and after 6 months of treatment with functional removable orthodontic appliances. Material/Methods The sample conisted of 51 patients with a mean age 10.7 years with Class II malocclusion. EMG recordings were performed by using a DAB-Bluetooth instrument (Zebris Medical GmbH, Germany). Recordings were performed in mandibular rest position, during maximum voluntary contraction (MVC), and during maximum effort. Results The results of the study indicated that the electrical activity of the muscles in each of the clinical situations was the same in the group of girls and boys. The factor that determined the activity of the muscles was their type. In mandibular rest position and in MVC, the activity of the temporalis muscles was significantly higher that that of the masseter muscels. The maximum effort test indicated a higher fatigue in masseter than in temporalis muscles. Conclusions Surface electromyography is a useful tool for monitoring muscle activity. A 6-month period of functional therapy resulted in changes in the activity of the masticatory muscles. PMID:25600247

Human brain activity associated with painful mechanical stimulation to muscle and bone.

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Maeda, Lynn; Ono, Mayu; Koyama, Tetsuo; Oshiro, Yoshitetsu; Sumitani, Masahiko; Mashimo, Takashi; Shibata, Masahiko

2011-08-01

The purpose of this study was to elucidate the central processing of painful mechanical stimulation to muscle and bone by measuring blood oxygen level-dependent signal changes using functional magnetic resonance imaging (fMRI). Twelve healthy volunteers were enrolled. Mechanical pressure on muscle and bone were applied at the right lower leg by an algometer. Intensities were adjusted to cause weak and strong pain sensation at either target site in preliminary testing. Brain activation in response to mechanical nociceptive stimulation targeting muscle and bone were measured by fMRI and analyzed. Painful mechanical stimulation targeting muscle and bone activated the common areas including bilateral insula, anterior cingulate cortex, posterior cingulate cortex, secondary somatosensory cortex (S2), inferior parietal lobe, and basal ganglia. The contralateral S2 was more activated by strong stimulation than by weak stimulation. Some areas in the basal ganglia (bilateral putamen and caudate nucleus) were more activated by muscle stimulation than by bone stimulation. The putamen and caudate nucleus may have a more significant role in brain processing of muscle pain compared with bone pain.

Experimental knee joint pain during strength training and muscle strength gain in healthy subjects

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Sørensen, T J; Langberg, Henning; Hodges, P W

2012-01-01

Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function...... and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals....

IB4(+) nociceptors mediate persistent muscle pain induced by GDNF.

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Alvarez, Pedro; Chen, Xiaojie; Bogen, Oliver; Green, Paul G; Levine, Jon D

2012-11-01

Skeletal muscle is a well-known source of glial cell line-derived neurotrophic factor (GDNF), which can produce mechanical hyperalgesia. Since some neuromuscular diseases are associated with both increased release of GDNF and intense muscle pain, we explored the role of GDNF as an endogenous mediator in muscle pain. Intramuscularly injected GDNF induced a dose-dependent (0.1-10 ng/20 μl) persistent (up to 3 wk) mechanical hyperalgesia in the rat. Once hyperalgesia subsided, injection of prostaglandin E(2) at the site induced a prolonged mechanical hyperalgesia (>72 h) compared with naïve rats (vibration increased muscle GDNF levels at 24 h, a time point where rats also exhibited marked muscle hyperalgesia. Intrathecal antisense oligodeoxynucleotides to mRNA encoding GFRα1, the canonical binding receptor for GDNF, reversibly inhibited eccentric exercise- and mechanical vibration-induced muscle hyperalgesia. Finally, electrophysiological recordings from nociceptors innervating the gastrocnemius muscle in anesthetized rats, revealed significant increase in response to sustained mechanical stimulation after local GDNF injection. In conclusion, these data indicate that GDNF plays a role as an endogenous mediator in acute and induction of chronic muscle pain, an effect likely to be produced by GDNF action at GFRα1 receptors located in IB4(+) nociceptors.

Does muscle morphology change in chronic neck pain patients? - A systematic review.

Science.gov (United States)

De Pauw, R; Coppieters, I; Kregel, J; De Meulemeester, K; Danneels, L; Cagnie, B

2016-04-01

Neck pain is a common disabling worldwide health problem with a high socio-economic burden. Changes underlying the transition to, or the maintenance of a chronic state are still barely understood. Increasing evidence suggests that morphological muscle changes, including changes in cross-sectional area (CSA) or fatty infiltration, play a role in chronic neck pain. However, a structured overview of the current evidence of morphological changes is lacking. To systematically review the morphological muscle changes in patients with chronic neck pain, including those with whiplash-associated disorders (WAD) and chronic idiopathic neck pain. A systematic review using the PRISMA-guidelines. Fourteen of 395 papers were included after extensive screening. Most studies were of moderate methodological quality. A higher CSA was found in all flexor muscles in both patients with WAD and patients with chronic idiopathic neck pain, except for the deeper flexor muscles in patients with chronic idiopathic neck pain. The cervical extensor muscles show an increased CSA at the highest cervical segments in patients with WAD, while most studies in patients with chronic idiopathic neck pain report a decreased CSA in all extensor muscles. Fatty infiltration, which could be accountable for an increased CSA, of both cervical extensors and flexors seems to occur only in patients with WAD. Some evidence is available for changes in muscle morphology, however more high quality prospective and cross-sectional research is needed to confirm these changes and to identify potential underlying causes that need yet to be discovered. Copyright © 2015 Elsevier Ltd. All rights reserved.

Muscle-tendon related pain in 100 patients with hip dysplasia: prevalence and associations with self-reported hip disability and muscle strength

DEFF Research Database (Denmark)

Jacobsen, Julie Sandell

2017-01-01

Introduction Intra-articular injury has been described as primary cause of pain in hip dysplasia. At this point, it is unknown whether external muscle-tendon related pain coexists with intra-articular pathology. The primary aim was to identify muscle-tendon related pain in 100 patients with hip...... dysplasia. The secondary aim was to test if muscle-tendon related pain is linearly associated to self-reported hip disability and muscle strength in patients with hip dysplasia. Materials and methods One hundred patients (17 men) with a mean age of 29+9 years were included. Clinical entity approach...... (phip dysplasia with a high...

The effect of unilateral partial edentulism to muscle thickness

International Nuclear Information System (INIS)

Koca-Ceylan, Golzem; Guler, Ahmet U.; Taskay-Yelmir, Nergiz; Lutfi, Incesu; Aksoz, Tolga

2003-01-01

Teeth and muscle play a very important role for occlusal equilibrium and function.when tooth loss begins ,it may also effect the function of muscle tissues. The thickness of masseter and anterior temporalis muscles were measured bilaterally in 30 healthy fully dentate adults and in 30 unilateral edentulous patients by using ultrasonographic imaging. All scans were carried out by the same radiologist to eliminate the inter-observer difference, using a real time scanner (Toshiba SSA -270A,Japan). A 7.5 MHz linear transducer was used. The effect of age, sex, duration of partial edentulism, unilateral chewing habits of the individuals to the muscle thickness were also evaluated. In all subjects,facial proportion index was also determined. Main purpose of this study was to compare and establish the differences of muscle thickness between dentate and edentulous side in unilateral partial edentulous patients with ultrasonography and to test whether the variation in the thickness of the muscle is related to the variation in the facial and morphology. Ultrasonography revealed a large variation in the thickness of the masseter and temporolis muscles in experimental and controlled groups ,both relaxed and contracted conditions.The thickness of muscles in females was less in both conditions.In experimental group, a high negative correlation was found between the thickness of the masseter muscle and Facial Proportion Index ( FPI) in the females ,however, the statistical analysis showed no significant difference in the males. Also a high negative correlation was found in female control group. There was no statistically significant relationship between unilateral chewing habits and muscle thickness .In this study the duration of partial edentulism did not affect the thickness of the muscle.Further research is required to study muscular atrophy for comparison with total edentulism. (author)

Influence of Baseline Psychological Health on Muscle Pain During Atorvastatin Treatment.

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Zaleski, Amanda L; Taylor, Beth A; Pescatello, Linda S; Dornelas, Ellen A; White, Charles Michael; Thompson, Paul D

3-hydroxy-3-methylglutaryl coenzyme A reductase reductase inhibitors (statins) are generally well tolerated, with statin-associated muscle symptoms (SAMS) the most common side effect (~10%) seen in statin users. However, studies and clinical observations indicate that many of the self-reported SAMS appear to be nonspecific (ie, potentially not attributable to statins). Mental health and well-being influence self-perception of pain, so we sought to assess the effect of baseline well-being and depression on the development of muscle pain with 6 months of atorvastatin 80 mg/d (ATORVA) or placebo in healthy, statin-naive adults. The Psychological General Well-being Index (n = 83) and Beck Depression Inventory (n = 55) questionnaires were administered at baseline in participants (aged 59.5 ± 1.2 years) from the effect of Statins on Skeletal Muscle Function and Performance (STOMP) trial (NCT00609063). Muscle pain (Short-Form McGill Pain Questionnaire [SF-MPQ]), pain that interferes with daily life (Brief Pain Inventory [BPI]), and pain severity (BPI) were then measured before, throughout, and after treatment. At baseline, there were no differences in well-being (Psychological General Well-being Index), depression (Beck Depression Inventory), or pain measures (SF-MPQ and BPI) (P values ≥ .05) between the placebo and ATORVA groups. Baseline well-being correlated negatively with baseline BPI pain severity (r = -0.290, P = .008). Baseline depression correlated with baseline pain (SF-MPQ; r = 0.314, P = .020). Baseline well-being and depression did not predict the change in pain severity or interference after 6 months among the total sample or between groups (P values ≥ .05). Baseline well-being and depression were not significant predictors of pain after 6 months of ATORVA (P values ≥ .05). Thus, they do not appear to increase the risk of SAMS in otherwise healthy adults.

Somatosensory sensitivity in patients with persistent idiopathic orofacial pain is associated with pain relief from hypnosis and relaxation.

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Baad-Hansen, Lene; Abrahamsen, Randi; Zachariae, Robert; List, Thomas; Svensson, Peter

2013-06-01

In a recent study hypnosis has been found to relieve persistent idiopathic orofacial pain. Quantitative sensory testing (QST) is widely used to evaluate somatosensory sensitivity, which has been suggested as a possible predictor of management outcome. The objectives of this study were to examine: (1) possible associations between clinical pain relief and baseline somatosensory sensitivity and (2) the effect of hypnosis management on QST parameters. Forty-one patients with persistent idiopathic orofacial pain completed this randomized controlled study in 1 of 2 groups: hypnosis (hypnotic analgesia suggestions) or control (relaxation). QST at 2 intraoral (pain region and contralateral mirror image region) and 3 extraoral (hand and both cheeks) sites was performed at baseline and after the hypnosis/control management, together with pressure pain thresholds and pressure pain tolerance thresholds determined bilaterally at the masseter and temporalis muscles, the temporomandibular joints, and the third finger. Degree of pain relief was negatively correlated with a summary statistic of baseline somatosensory sensitivity (summed z-score), that is, high baseline somatosensory sensitivity was associated with low pain relief (r=-0.372, P=0.020). Hypnosis had no major effect on any QST measure compared with relaxation (P>0.063). High pain sensitivity at baseline may predict poor pain management outcome. In addition, despite clear clinical pain relief, hypnosis did not significantly or specifically influence somatosensory sensitivity. Future studies should further explore QST measures as possible predictors of different management response in orofacial pain conditions.

Electromyographic activity of masticatory muscles in elderly women – a pilot study

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Gaszynska E

2017-01-01

Full Text Available Ewelina Gaszynska,1 Karolina Kopacz,2 Magdalena Fronczek-Wojciechowska,2 Gianluca Padula,2 Franciszek Szatko1 1Department of Hygiene and Health Promotion, 2Academic Laboratory of Movement and Human Physical Performance “DynamoLab”, Medical University of Lodz, Lodz, PolandObjectives: To evaluate the effect of age and chosen factors related to aging such as dentition, muscle strength, and nutrition on masticatory muscles electromyographic activity during chewing in healthy elderly women.Background: With longer lifespan there is a need for maintaining optimal quality of life and health in older age. Skeletal muscle strength deteriorates in older age. This deterioration is also observed within masticatory muscles.Methods: A total of 30 women, aged 68–92 years, were included in the study: 10 indivi­duals had natural functional dentition, 10 were missing posterior teeth in the upper and lower jaw reconstructed with removable partial dentures, and 10 were edontoulous, using complete removable dentures. Surface electromyography was performed to evaluate masticatory muscles activity. Afterwards, measurement of masseter thickness with ultrasound imaging was performed, body mass index and body cell mass index were calculated, and isometric handgrip strength was measured.Results: Isometric maximal voluntary contraction decreased in active masseters with increasing age and in active and passive temporalis muscles with increasing age and increasing body mass index. In active masseter, mean electromyographic activity during the sequence (time from the start of chewing till the end when the test food became ready to swallow decreased with increasing age and during the cycle (single bite time decreased with increasing age and increasing body mass index. In active and passive temporalis muscles, mean electromyographic activity during the sequence and the cycle decreased with increasing age, increasing body mass index, and loss of natural dentition

Abnormal muscle afferent function in a model of Taxol chemotherapy-induced painful neuropathy

OpenAIRE

Chen, Xiaojie; Green, Paul G.; Levine, Jon D.

2011-01-01

Despite muscle pain being a well-described symptom in patients with diverse forms of peripheral neuropathy, the role of neuropathic mechanisms in muscle pain have received remarkably little attention. We have recently demonstrated in a well-established model of chemotherapy-induced painful neuropathy (CIPN) that the anti-tumor drug paclitaxel (Taxol) produces mechanical hyperalgesia in skeletal muscle, of similar time course to and with shared mechanism with cutaneous symptoms. In the present...

Densities and sizes of the main masticatory muscles in computed tomography compared with clinical findings related to temporo mandibular joint (TMJ) dysfunction

International Nuclear Information System (INIS)

Raustia, A.M.; Pyhtinen, J.; Virtanen, K.K.; Oulu Univ.

1986-01-01

Computed tomography (CT) has a good resolution capacity and is an excellent method for measuring tissue densities. The aim here was to compare the densities and sizes of the main masticatory muscles, the masseter, medial pterygoid and lateral pterygoid muscles, as obtained with CT, with clinical findings in patients with TMJ dysfunction (25) and controls (29). The densities of the masseter muscles and the medial pterygoid muscles showed no statistical difference between the patients and controls, while the lateral pterygoid muscles of the patients had densities that were only almost significantly higher than those of the controls. The masseter muscles on the patients who more often had signs of bruxism in their dentition were statistically significantly thicker than in the controls, but the widths of the medial pterygoid muscles gave no statistical difference between the groups. The results seem to indicate that in addition to the bone density changes associated with functional disorders of the masticatory system, there may be also density and size changes in the masticatory muscles which are detectable by CT. (orig.) [de

Densities and sizes of the main masticatory muscles in computed tomography compared with clinical findings related to temporo mandibular joint (TMJ) dysfunction

Energy Technology Data Exchange (ETDEWEB)

Raustia, A.M.; Pyhtinen, J.; Virtanen, K.K.

1986-03-01

Computed tomography (CT) has a good resolution capacity and is an excellent method for measuring tissue densities. The aim here was to compare the densities and sizes of the main masticatory muscles, the masseter, medial pterygoid and lateral pterygoid muscles, as obtained with CT, with clinical findings in patients with TMJ dysfunction (25) and controls (29). The densities of the masseter muscles and the medial pterygoid muscles showed no statistical difference between the patients and controls, while the lateral pterygoid muscles of the patients had densities that were only almost significantly higher than those of the controls. The masseter muscles on the patients who more often had signs of bruxism in their dentition were statistically significantly thicker than in the controls, but the widths of the medial pterygoid muscles gave no statistical difference between the groups. The results seem to indicate that in addition to the bone density changes associated with functional disorders of the masticatory system, there may be also density and size changes in the masticatory muscles which are detectable by CT.

Mandibular angle resection and masticatory muscle hypertrophy - a technical note and morphological optimization.

Science.gov (United States)

Andreishchev, A R; Nicot, R; Ferri, J

2014-11-01

Mandibular angle resection is rarely used, but is a highly effective means of correcting facial defects. We report a mandibular angle resection technique associated with the removal of a part of hypertrophic masseter muscles and resection of buccal fat pad. Anatomical reminders: the most important entities are the facial artery and vein, crossing the lower margin of the jaw just in front of the anterior boarder of the masseter muscle and the temporomaxillary vein, passing through the temporomaxillary fossa; preoperative aspects: the preoperative examination included a radiological assessment of the shape and size of the mandibular angle; surgical technique: an intra-oral approach was usually used. The most effective and convenient method for the osteotomy was using a reciprocating saw. This technique allowed achieving a smooth contour of masseter muscles during masticatory movements or at rest. Eleven mandibular angle resections were performed from 2001 to 2009. The surgery was supplemented by remodeling the lower margin of the jaw for 5 other patients. No permanent facial palsy was noted. One patient presented a unilateral long-term loss of sensitivity of the lower lip and chin. This surgical technique if simple even requires using good technical equipment, and observing a set of rules. Using these principles allows simplifying the surgical technique, and decreasing its morbidity. A part of the masseter muscles and the buccal fat pad can sometimes be resected to improve the morphological results. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Relationships among head posture, pain intensity, disability and deep cervical flexor muscle performance in subjects with postural neck pain

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Arun V. Subbarayalu, PhD

2017-12-01

Full Text Available Objectives: Information Technology (IT professionals working with computers gradually develop forward head posture and, as a result, these professionals are susceptible to several neck disorders. This study intended to reveal the relationships between pain intensity, disability, head posture and deep cervical flexor (DCF muscle performance in patients with postural neck pain. Methods: A cross-sectional study was conducted on 84 IT professionals who were diagnosed with postural neck pain. The participants were recruited with a random sampling approach. A Visual Analogue Scale (VAS, the Northwick Park Neck Pain Questionnaire (NPQ, the Modified Head Posture Spinal Curvature Instrument (MHPSCI, and the Stabilizer Pressure Biofeedback Unit were used to measure neck pain intensity, neck disability, head posture, and DCF muscle performance, respectively. Results: The Pearson correlation coefficient revealed a significantly strong positive relationship between the VAS and the NPQ (r = 0.734. The cranio-vertebral (CV angle was found to have a significantly negative correlation with the VAS (r = −0.536 and a weak negative correlation with the NPQ (r = −0.389. Conclusion: This study concluded that a smaller CV angle corresponded to greater neck pain intensity and disability. Furthermore, there is no significant relationship between CV angle and DCF muscle performance, indicating that head posture re-education through postural correction exercises would not completely correct the motor control deficits in DCF muscles. In addition, a suitable exercise regimen that exclusively targets the deep cervical flexor muscle to improve its endurance is warranted. Keywords: Craniovertebral angle, Disability deep cervical flexors muscle performance, Head posture, Postural neck pain

Swelling of the temporal region: a case of benign masticatory muscle hypertrophy

DEFF Research Database (Denmark)

Gniadecka, M; Weismann, K; Herning, Gudrun Margrethe

1997-01-01

A 35-year-old Caucasian woman had bilateral indolent swelling of the temporal regions. Imaging studies with nuclear magnetic resonance, ultrasonography and histopathological investigation revealed enlargement of the temporal and masseter muscles, with no pathology in the skin or subcutaneous tiss....... A small prolactinoma of the pituitary gland was incidentally found. The condition, designated benign masticatory muscle hypertrophy, should be distinguished from similar diseases affecting the skin and the subcutaneous tissue of the scalp. The cause remains unknown......A 35-year-old Caucasian woman had bilateral indolent swelling of the temporal regions. Imaging studies with nuclear magnetic resonance, ultrasonography and histopathological investigation revealed enlargement of the temporal and masseter muscles, with no pathology in the skin or subcutaneous tissue...

The local and referred pain from myofascial trigger points in the temporalis muscle contributes to pain profile in chronic tension-type headache.

Science.gov (United States)

Fernández-de-Las-Peñas, César; Ge, Hong-You; Arendt-Nielsen, Lars; Cuadrado, Maria Luz; Pareja, Juan A

2007-01-01

To assess the local and referred pain areas and pain characteristics evoked from temporalis muscle trigger points (TrPs) in chronic tension-type headache (CTTH). Thirty CTTH patients and 30 age and sex-matched controls were studied. A headache diary was kept for 4 weeks to substantiate the diagnosis and record the pain history. Both temporalis muscles were examined for the presence of myofascial TrPs in a blinded fashion. The local and referred pain intensities, referred pain pattern, and pressure pain threshold were recorded. Referred pain was evoked in 87% and 54% on the dominant and nondominant sides in CTTH patients, which was significantly higher (P<0.001) than in controls (10% vs. 17%, respectively). Referred pain spread to the temple ipsilateral to the stimulated muscle in both patients and controls, with additional referral behind the eyes in most patients, but none in controls. CTTH patients reported a higher local [visual analog scale (VAS): 5.6+/-1.2 right side, 5.3+/-1.4 left side] and referred pain (VAS: 4.7+/-2 right side, 3.5+/-2.8 left side) intensity than healthy controls (VAS: 0.8+/-0.7 right side, 0.7+/-0.7 left side for local pain; and 0.3+/-0.2 right side, 0.4+/-0.3 left side for referred pain) in both temporalis muscles (both, P<0.001). The local and referred pain areas were larger in patients than in controls (P<0.001). Twenty-three out of 30 CTTH patients (77%) had active TrPs in the temporalis muscle leading to their usual headache (17 patients on the right side; 12 on the left side, whereas 6 with bilateral active TrPs). CTTH patients with active TrPs in either right or left temporalis muscle showed longer headache duration than those with latent TrPs (P=0.004). CTTH patients showed significantly (P<0.001) lower pressure pain threshold (1.1+/-0.2 right side, 1.2+/-0.3 left side) as compared with controls (2.5+/-0.5 right side, 2.6+/-0.4 left side). In CTTH patients, the evoked local and referred pain from active TrPs in the temporalis

Exercise despite pain – breast cancer patient experiences of muscle and joint pain during adjuvant chemotherapy and concurrent participation in an exercise intervention

DEFF Research Database (Denmark)

Andersen, Christina; Rørth, M; Ejlertsen, B

2014-01-01

Chemotherapy-related pain is a well-known side effect in cancer patient receiving chemotherapy. However, limited knowledge exists describing whether exercise exacerbates existing pain. Aim of the research was to explore muscle and joint pain experienced by women with breast cancer receiving...... intervention comprised supervised training: high-intensity cardiovascular, heavy resistance and relaxation, massage and body-awareness (9 h weekly, 6 weeks). The analysis revealed five categories: Abrupt pain - a predominant side effect, cogitated pain management, the adapted training, non......-immediate exacerbation of pain and summarised into the essence of chemotherapy related muscle and joint pain in exercise breast cancer patients; exercise despite pain. Findings indicate that the patients' perception of sudden onset of chemotherapy-related muscle and joint pain was not aggravated by training. Pain...

[Pure trigeminal motor neuropathy presenting with temporo-mandibular joint dysfunction in a patient with HIV and HCV infections].

Science.gov (United States)

Anheim, M; Echaniz-Laguna, A; Rey, D; Tranchant, C

2006-01-01

Pure trigeminal motor neuropathy (PTMN) is a rarely described condition. We report the case of a 41-year-old woman infected with the human immunodeficiency virus (HIV1) and hepatitis C virus who presented with weakness of left temporalis and masseter muscles and painful left temporomandibular joint dysfunction (TMD) a few months after cerebral toxoplasmosis revealing acquired immunodeficiency syndrome (AIDS). Magnetic resonance imaging revealed severe wasting and fat replacement of the left temporalis, pterygoid and masseter muscles and showed neither abnormalities in the left motor nucleus of the trigeminal nerve nor compression of the left trigeminal nerve. Electromyographic examination gave evidence of denervation in the left temporalis, masseter and pterygoid muscles and blink reflex studies were normal, confirming the diagnosis of PTMN which was probably secondary to HIV and HCV co-infection.

Incidence of centrally positioned nuclei in mouse masticatory muscle fibers

DEFF Research Database (Denmark)

Vilmann, A; Vilmann, H; Kirkeby, S

1989-01-01

Cross-sections of normal digastric, temporalis and masseter muscles from 7- and 30-week-old mice were studied for centrally positioned nuclei. Such nuclei were inhomogeneously distributed throughout each muscle and varied markedly between specimens. The incidence of centrally positioned nuclei in...

Does a Better Perfusion of Deconditioned Muscle Tissue Release Chronic Low Back Pain?

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Paola Valdivieso

2018-03-01

Full Text Available Non-specific chronic low back pain (nsCLBP is a multifactorial condition of unknown etiology and pathogenesis. Physical and genetic factors may influence the predisposition of individuals to CLBP, which in many instances share a musculoskeletal origin. A reduced pain level in low back pain patients that participate in exercise therapy highlights that disuse-related muscle deconditioning may predispose individuals to nsCLBP. In this context, musculoskeletal pain may be the consequence of capillary rarefaction in inactive muscle as this would lower local tissue drainage and washing out of toxic waste. Muscle activity is translated into an angio-adaptative process, which implicates angiogenic-gene expression and individual response differences due to heritable modifications of such genes (gene polymorphisms. The pathophysiologic mechanism underlying nsCLBP is still largely unaddressed. We hypothesize that capillary rarefaction due to a deconditioning of dorsal muscle groups exacerbates nsCLBP by increasing noxious sensation, reducing muscle strength and fatigue resistance by initiating a downward spiral of local deconditioning of back muscles which diminishes their load-bearing capacity. We address the idea that specific factors such as angiotensin-converting enzyme and Tenascin-C might play an important role in altering susceptibility to nsCLBP via their effects on microvascular perfusion and vascular remodeling of skeletal muscle, inflammation, and pain sensation. The genetic profile may help to explain the individual predisposition to nsCLBP, thus identifying subgroups of patients, which could benefit from ad hoc treatment types. Future therapeutic approaches aimed at relieving the pain associated with nsCLBP should be based on the verification of mechanistic processes of activity-induced angio-adaptation and muscle-perfusion.

Influence of changing occlusal support on jaw-closing muscle electromyographic activity in healthy men and women.

Science.gov (United States)

Wang, Mei-Qing; He, Jian-Jun; Wang, Kelun; Svensson, Peter

2009-01-01

To test whether changes in occlusal support differentially modulate masseter and anterior temporalis muscle electromyographic (EMG) activity during controlled maximal voluntary clenching. Forty-seven healthy subjects (32 M and 15 F, 22.9+/-1.3 years) were recruited. Cotton-rolls were used to modify the occlusal contact relations and were positioned on the right, left, or both sides, and either in the molar or premolar regions, i.e. six different occlusal combinations. Surface EMG activity was recorded bilaterally from the masseter and anterior temporalis area and normalized with respect to maximal voluntary clenching in the intercuspal position. Analysis of variance and the paired t-test were used to test the data. Normalized EMG activity was influenced by changes in cotton-roll modified occlusal support, and there were differences between muscles (pocclusal support was moved from the molar to the premolar region. When occlusal support was moved from bilateral to unilateral contacts, EMG activity in the balancing-side anterior temporalis muscle and in bilateral masseter muscles decreased. Unilateral clenching on the molars, but not on the premolars, was associated with lower EMG activity in the balancing-side masseter and always associated with lower EMG activity in the balancing-side anterior temporalis compared to the working side (pocclusal support, which may have implications for stability of the mandible during intense clenching.

The alterations in adenosine nucleotides and lactic acid in striated muscles of rats during Rigor mortis following death with drowning or cervical dislocation.

Science.gov (United States)

Pençe, Halime Hanim; Pençe, Sadrettin; Kurtul, Naciye; Yilmaz, Necat; Kocoglu, Hasan; Bakan, Ebubekir

2003-01-01

In this study, adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP) and lactic acid in the muscles of masseter, triceps, and quadriceps obtained from right and left sides of Spraque-Dawley rats following death were investigated. The samples were taken immediately and 120 minutes after death occurred. The rats were killed either by cervical dislocation or drowning. ATP concentrations in the muscles of masseter, triceps, and quadriceps were lower in samples obtained 120 minutes after death than in those obtained immediately after death. ADP, AMP, and lactic acid concentrations in these muscles were higher in samples obtained 120 minutes after death than those obtained immediately after death. A positive linear correlation was determined between ATP and ADP concentrations in quadriceps muscles of the rats killed with cervical dislocation and in triceps muscles of the rats killed with drowning. When rats killed with cervical dislocation and with drowning were compared, ADP, AMP, and lactic acid concentrations were lower in the former than in the latter for both times (immediately and 120 minutes after death occurred). In the case of drowning, ATP is consumed faster because of hard exercise or severe physical activity, resulting in a faster rigor mortis. Higher lactic acid levels were determined in muscles of the rats killed with drowning than the other group. In the control and electric shock rats, ATP decreased in different levels in the three different muscle types mentioned above in control group, being much decline in masseter and then in quadriceps. This may be caused by lower mass and less glycogen storage of masseter. No different ATP levels were measured in drowning group with respect to the muscle type possibly because of the severe activity of triceps and quadriceps and because of smaller mass of masseter. One can conclude that the occurrence of rigor mortis is closely related to the mode of death.

Impact of pain reported during isometric quadriceps muscle strength testing in people with knee pain: data from the osteoarthritis initiative.

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Riddle, Daniel L; Stratford, Paul W

2011-10-01

Muscle force testing is one of the more common categories of diagnostic tests used in clinical practice. Clinicians have little evidence to guide interpretations of muscle force tests when pain is elicited during testing. The purpose of this study was to examine the construct validity of isometric quadriceps muscle strength tests by determining whether the relationship between maximal isometric quadriceps muscle strength and functional status was influenced by pain during isometric testing. A cross-sectional design was used. Data from the Osteoarthritis Initiative were used to identify 1,344 people with unilateral knee pain and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale scores of 1 or higher on the involved side. Measurements of maximal isometric quadriceps strength and ratings of pain during isometric testing were collected. Outcome variables were WOMAC physical function subscale, 20-m walk test, 400-m walk test, and a repeated chair stand test. Multiple regression models were used to determine whether pain during testing modified or confounded the relationship between strength and functional status. Pearson r correlations among the isometric quadriceps strength measures and the 4 outcome measures ranged from -.36 (95% confidence interval=-.41, -.31) for repeated chair stands to .36 (95% confidence interval=.31, .41) for the 20-m walk test. In the final analyses, neither effect modification nor confounding was found for the repeated chair stand test, the 20-m walk test, the 400-m walk test, or the WOMAC physical function subscale. Moderate or severe pain during testing was weakly associated with reduced strength, but mild pain was not. The disease spectrum was skewed toward mild or moderate symptoms, and the pain measurement scale used during muscle force testing was not ideal. Given that the spectrum of the sample was skewed toward mild or moderate symptoms and disease, the data suggest that isometric quadriceps muscle

Muscle-specific integrins in masseter muscle fibers of chimpanzees: an immunohistochemical study.

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Gianluigi Vaccarino

2010-05-01

Full Text Available Most notably, recent comparative genomic analyses strongly indicate that the marked differences between modern human and chimpanzees are likely due more to changes in gene regulation than to modifications of the genes. The most peculiar aspect of hominoid karyotypes is that human have 46 chromosomes whereas gorillas and chimpanzees have 48. Interestingly, human and chimpanzees do share identical inversions on chromosome 7 and 9 that are not evident in the gorilla karyotype. Thus, the general phylogeny suggests that humans and chimpanzees are sister taxa; based on this, it seems that human-chimpanzee sequence similarity is an astonishing 99%. At this purpose, of particular interest is the inactivation of the myosin heavy chain 16 (MYH16 gene, most prominently expressed in the masticatory muscle of mammals. It has been showed that the loss of this gene in humans may have resulted in smaller masticatory muscle and consequential changes to cranio-facial morphology and expansion of the human brain case. Powerful masticatory muscles are found in most primates; contrarily, in both modern and fossil member Homo, these muscles are considerably smaller. The evolving hominid masticatory apparatus shifted towards a pattern of gracilization nearly simultaneously with accelerated encephalization in early Homo. To better comprehend the real role of the MYH16 gene, we studied the primary proteins present in the muscle fibers of humans and non-humans, in order to understand if they really can be influenced by MYH16 gene. At this aim we examined the muscle-specific integrins, alpha 7B and beta 1D-integrins, and their relative fetal isoforms, alpha 7A and beta 1A-integrins, analyzing, by immunohistochemistry, muscle biopsies of two components of a chimpanzee's group in captivity, an alpha male and a non-alpha male subjects; all these integrins participate in vital biological processes such as maintenance of tissue integrity, embryonic development, cell

Referred pain elicited by manual exploration of the lateral rectus muscle in chronic tension-type headache.

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Fernández-de-Las-Peñas, César; Cuadrado, Maria Luz; Gerwin, Robert D; Pareja, Juan A

2009-01-01

To analyze the presence of referred pain elicited by manual examination of the lateral rectus muscle in patients with chronic tension-type headache (CTTH). A case-control blinded study. It has been found previously that the manual examination of the superior oblique muscle can elicit referred pain to the head in some patients with migraine or tension-type headache. However, a referred pain from other extraocular muscles has not been investigated. Fifteen patients with CTTH and 15 healthy subjects without headache history were included. A blinded assessor performed a manual examination focused on the search for myofascial trigger points (TrPs) in the right and left lateral rectus muscles. TrP diagnosis was made when there was referred pain evoked by maintained pressure on the lateral corner of the orbit (anatomical projection of the lateral rectus muscle) for 20 seconds, and increased referred pain while the subject maintained a medial gaze on the corresponding side (active stretching of the muscle) for 15 seconds. On each side, a 10-point numerical pain rate scale was used to assess the intensity of referred pain at both stages of the examination. Ten patients with CTTH (66.6%) had referred pain that satisfied TrPs diagnostic criteria, while only one healthy control (0.07%) reported referred pain upon the examination of the lateral rectus muscles (P < 0.001). The elicited referred pain was perceived as a deep ache located at the supraorbital region or the homolateral forehead. Pain was evoked on both sides in all subjects with TrPs, with no difference in pain intensity between the right and the left. The average pain intensity was significantly greater in the patient group (P < 0.001). All CTTH patients with referred pain recognized it as the frontal pain that they usually experienced during their headache attacks, which was consistent with active TrPs. In some patients with CTTH, the manual examination of lateral rectus muscle TrPs elicits a referred pain that

Efficiency of deep core muscles training on patients with low back pain

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Povilauskaitė, Ieva

2017-01-01

Efficiency of Deep Core Muscles Training on Patients with Low Back Pain Vilnius University Faculty of Medicine Department of Rehabilitation, Physical and Sports Medicine Bachelor Degree of Physiotherapy Efficiency of Deep Core Muscles Strengthening Exercises on Patients with Low Back Pain Physiotherapy Bachelor's Thesis The Author: Ieva Povilauskaitė Academic advisor: Lecturer dr. Ieva Eglė Jamontaitė The aim of research work: measure the efficiency of come muscles strengthening exercises in ...

Repeated tongue lift movement induces neuroplasticity in corticomotor control of tongue and jaw muscles in humans

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Komoda, Yoshihiro; Lida, Takashi; Kothari, Mohit

2015-01-01

. EMG recordings from the left and right tongue dorsum and masseter muscles were made at three pressure levels (5kPa, 10kPa, 100% tongue lift), and tongue, masseter, and first dorsal interosseous (FDI) MEPs were measured. There were no significant day-to-day differences in the tongue pressure during...

Muscle fatigue in relation to forearm pain and tenderness among professional computer users

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Thomsen, GF; Johnson, PW; Svendsen, Susanne Wulff

2007-01-01

ABSTRACT: BACKGROUND: To examine the hypothesis that forearm pain with palpation tenderness in computer users is associated with increased extensor muscle fatigue. METHODS: Eighteen persons with pain and moderate to severe palpation tenderness in the extensor muscle group of the right forearm...... response was not explained by differences in the MVC or body mass index. CONCLUSION: Computer users with forearm pain and moderate to severe palpation tenderness had diminished forearm extensor muscle fatigue response. Additional studies are necessary to determine whether this result reflects an adaptive...... and twenty gender and age matched referents without such complaints were enrolled from the Danish NUDATA study of neck and upper extremity disorders among technical assistants and machine technicians. Fatigue of the right forearm extensor muscles was assessed by muscle twitch forces in response to low...

Craniofacial Pain: Brainstem Mechanisms

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Barry J Sessle

1996-01-01

Full Text Available This article reviews recent research advances in animals that have identified critical neural elements in the brainstem receiving and transmitting craniofacial nociceptive inputs, as well as some of the mechanisms involved in the modulation and plasticity of nociceptive transmission. Nociceptive neurones in the trigeminal (V brainstem sensory nuclear complex can be classified as nociceptive-specific (NS or wide dynamic range (WDR. Some of these neurones respond exclusively to sensory inputs evoked by stimulation of facial skin or oral mucosa and have features suggesting that they are critical neural elements involved in the ability to localize an acute superficial pain and sense its intensity and duration. Many of the V brainstem nociceptive neurones, however, receive convergent inputs from afferents supplying deep craniofacial tissues (eg, dural vessel, muscle and skin or mucosa. These neurones are likely involved in deep pain, including headache, because few nociceptive neurones receive inputs exclusively from afferents supplying these tissues. These extensive convergent input patterns also appear to be important factors in pain spread and referral, and in central mechanisms underlying neuroplastic changes in V neuronal properties that may occur with injury and inflammation. For example, application of the small fibre excitant and inflammatory irritant mustard oil into the temporomandibular joint, masseter or tongue musculature induces a prolonged but reversible enhancement of responses to cutaneous and deep afferent inputs of most WDR and NS neurones. These effects may be accompanied by increased electromyographic activity reflexly induced in the masticatory muscles by mustard oil, and involve endogenous N-methyl-D-aspartate and opioid neurochemical mechanisms. Such peripherally induced modulation of brainstem nociceptive neuronal properties reflects the functional plasticity of the central V system, and may be involved in the development of

Involvement of trigeminal transition zone and laminated subnucleus caudalis in masseter muscle hypersensitivity associated with tooth inflammation.

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Kohei Shimizu

Full Text Available A rat model of pulpitis/periapical periodontitis was used to study mechanisms underlying extraterritorial enhancement of masseter response associated with tooth inflammation. Periapical bone loss gradually increased and peaked at 6 weeks after complete Freund's adjuvant (CFA application to the upper molar tooth pulp (M1. On day 3, the number of Fos-immunoreactive (IR cells was significantly larger in M1 CFA rats compared with M1 vehicle (veh rats in the trigeminal subnucleus interpolaris/caudalis transition zone (Vi/Vc. The number of Fos-IR cells was significantly larger in M1 CFA and masseter (Mass capsaicin applied (M1 CFA/Mass cap rats compared with M1 veh/Mass veh rats in the contralateral Vc and Vi/Vc. The number of phosphorylated extracellular signal-regulated kinase (pERK-IR cells was significantly larger in M1 CFA/Mass cap and M1 veh/Mass cap rats compared to Mass-vehicle applied rats with M1 vehicle or CFA in the Vi/Vc. Pulpal CFA application caused significant increase in the number of Fos-IR cells in the Vi/Vc but not Vc on week 6. The number of pERK-IR cells was significantly lager in the rats with capsaicin application to the Mass compared to Mass-vehicle treated rats after pulpal CFA- or vehicle-application. However, capsaicin application to the Mass did not further affect the number of Fos-IR cells in the Vi/Vc in pulpal CFA-applied rats. The digastric electromyographic (d-EMG activity after Mass-capsaicin application was significantly increased on day 3 and lasted longer at 6 weeks after pulpal CFA application, and these increase and duration were significantly attenuated by i.t. PD98059, a MEK1 inhibitor. These findings suggest that Vi/Vc and Vc neuronal excitation is involved in the facilitation of extraterritorial hyperalgesia for Mass primed with periapical periodontitis or acute pulpal-inflammation. Furthermore, phosphorylation of ERK in the Vi/Vc and Vc play pivotal roles in masseter hyperalgesia after pulpitis or

Muscle activity pattern dependent pain development and alleviation

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Sjøgaard, Gisela; Søgaard, Karen

2014-01-01

Muscle activity is for decades considered to provide health benefits irrespectively of the muscle activity pattern performed and whether it is during e.g. sports, transportation, or occupational work tasks. Accordingly, the international recommendations for public health-promoting physical activity...... do not distinguish between occupational and leisure time physical activity. However, in this body of literature, attention has not been paid to the extensive documentation on occupational physical activity imposing a risk of impairment of health - in particular musculoskeletal health in terms...... during physical activities at leisure and sport the motor recruitment patterns are more dynamic including regularly relatively high muscle forces - also activating type 2 muscles fibers - as well as periods of full relaxation even of the type 1 muscle fibers. Such activity is unrelated to muscle pain...

IGF and myostatin pathways are respectively induced during the earlier and the later stages of skeletal muscle hypertrophy induced by clenbuterol, a β₂-adrenergic agonist.

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Abo, Tokuhisa; Iida, Ryo-Hei; Kaneko, Syuhei; Suga, Takeo; Yamada, Hiroyuki; Hamada, Yoshiki; Yamane, Akira

2012-12-01

Clenbuterol, a β₂-adrenergic agonist, increases the hypertrophy of skeletal muscle. Insulin-like growth factor (IGF) is reported to work as a potent positive regulator in the clenbuterol-induced hypertrophy of skeletal muscles. However, the precise regulatory mechanism for the hypertrophy of skeletal muscle induced by clenbuterol is unknown. Myostatin, a member of the TGFβ super family, is a negative regulator of muscle growth. The aim of the present study is to elucidate the function of myostatin and IGF in the hypertrophy of rat masseter muscle induced by clenbuterol. To investigate the function of myostatin and IGF in regulatory mechanism for the clenbuterol-induced hypertrophy of skeletal muscles, we analysed the expression of myostatin and phosphorylation levels of myostatin and IGF signaling components in the masseter muscle of rat to which clenbuterol was orally administered for 21 days. Hypertrophy of the rat masseter muscle was induced between 3 and 14 days of oral administration of clenbuterol and was terminated at 21 days. The expression of myostatin and the phosphorylation of smad2/3 were elevated at 21 days. The phosphorylation of IGF receptor 1 (IGFR1) and akt1 was elevated at 3 and 7 days. These results suggest that myostatin functions as a negative regulator in the later stages in the hypertrophy of rat masseter muscle induced by clenbuterol, whereas IGF works as a positive regulator in the earlier stages. Copyright © 2012 John Wiley & Sons, Ltd.

The Relationship between Walk Distance and Muscle Strength, Muscle Pain in Visually Disabled People

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Akyol, Betül

2018-01-01

The purpose of this study is to examine the relationship between six-minute walk test and muscle pain, muscle strength in visually disabled people. The study includes 50 visually disabled people, aged between 17, 21 ± 5,3. Participants were classified into three categories according to their degree of vision (B1, B2, B3). All participants were…

Low back pain characterized by muscle resistance and occupational factors associated with nursing

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Rafael de Souza Petersen

2014-06-01

Full Text Available OBJECTIVE: to identify the occupational factors associated with low back pain using a surveillance tool and to characterize the low back pain by the resistance of the extensor muscles of the vertebral column among nursing professionals at an Intensive Care Unit.METHODS: Cross-sectional study. The workers answered a questionnaire about occupational factors and participated in a resistance test of the extensor muscles of the vertebral column. Associations were established through Student's T-test or Mann-Whitney's U-test and correlations using Pearson's test.RESULTS: Out of 48 participants, 32 (67% suffered from low pain. For the resistance test, the subjects suffering from low back pain endured less time in comparison with asymptomatic subjects, but without significant differences (p=0.147. The duration of the pain episode showed a significant negative correlation (p=0.016 with the results of the resistance test though. The main factors identified as causes of low back pain were biomechanical and postural elements, conditions of the muscle structure and physical and organizational conditions.CONCLUSIONS: the main occupational factors associated with the low back pain were the posture and the characteristics of the physical and organizational conditions. In addition, the extensor muscles of the column showed a trend towards lesser resistance for workers in pain. This evidence is important when considering prevention and treatment strategies.

Estudo eletromiográfico do músculo masseter durante o apertamento dentário e mastigação habitual em adultos com oclusão dentária normal Electromyographic study of the masseter muscle during maximal voluntary clenching and habitual chewing in adults with normal occlusion

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Adriana Rahal

2009-01-01

Full Text Available OBJETIVO: Analisar a diferença entre os lados na atividade eletromiográfica do masseter em indivíduos adultos com oclusão dentária normal. MÉTODOS: Foram avaliados 30 indivíduos saudáveis entre 21 e 30 anos e realizou-se eletromiografia de superfície nos músculos masseteres direito e esquerdo, durante apertamento em máxima intercuspidação e mastigação habitual com uva passa. Foram computados os valores médios dos três apertamentos dentários e dos 15 segundos da mastigação habitual para cada indivíduo. Foram considerados para a análise: o lado de maior valor e o de menor valor eletromiográfico. RESULTADOS: Durante o apertamento dentário, a diferença média entre os dois lados foi de 20,0 microvolts (μV com intervalo de confiança (95% entre 14,0 e 26,0 μV e durante a mastigação habitual, a diferença média entre os dois lados foi de 10,3 μV com intervalo de confiança (95% entre 6,7 e 13,8 μV. CONCLUSÃO: Houve diferença estatisticamente significante entre os lados, com relação entre eles de 24% para o apertamento dentário e de 27% para a mastigação habitual, em indiv duos adultos saudáveis.PURPOSE: To analyze the difference between both sides of the face during the electromyographic activity of the masseter muscle in adults with normal occlusion. METHODS: Thirty healthy individuals with ages ranging from 21 to 30 years old were selected. Surface electromyography was performed on right and left masseter muscles during maximal voluntary clenching and habitual chewing with raisins. The mean values of three teeth clenching and fifteen seconds of habitual chewing were calculated for each subject. The analysis considered the sides with higher and lower electromyographic activity. RESULTS: During maximal voluntary clenching, the mean difference between sides was 20.0 microvolts (μV, with confidence interval (95% between 14.0 and 26.0 μV. During habitual chewing, the mean difference between sides was 10.3 �

Co-contraction behaviour of masticatory and neck muscles during tooth grinding.

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Giannakopoulos, N N; Schindler, H J; Hellmann, D

2018-07-01

The objective of this study was to analyse the co-contraction behaviour of jaw and neck muscles during force-controlled experimental grinding in the supine position. Twelve symptom-free subjects were enrolled in the experimental study. Electromyographic (EMG) activity of semispinalis capitis, splenius capitis and levator scapulae muscles was recorded bilaterally with intramuscular fine-wire electrodes, whereas that of sternocleidomastoideus, infrahyoidal, suprahyoidal, masseter and anterior temporalis muscles were registered with surface electrodes. EMG and force measurements were performed during tasks simulating tooth grinding on custom-made intraoral metal splints. The mean EMG activity normalised by maximum voluntary contraction (% MVC) of each of the neck muscles studied during grinding was analysed and compared with previous data from jaw clenching at identical force (100 N) and (supine) position. The occurrence of low-level, long-lasting tonic activation (LLTA) of motor units was also documented. The mean three-dimensional force vector of the grinding forces was 106 ± 74 N. In the frontal plane, the incline to the midsagittal plane ranged between 10° and 15°. In the midsagittal plane, the incline to the frontal plane was negligibly small. Posterior neck muscle activity during grinding ranged between 4.5% and 12% MVC and during clenching with 100 N between 1.8% and 9.9% MVC. Masticatory muscle activity during grinding ranged between 17% and 21% MVC for contralateral masseter and ipsilateral temporalis and between 4% and 6.5% for ipsilateral masseter and contralateral temporalis. LLTA had an average duration of 195 ± 10 seconds. The findings from this study do not support pathophysiological muscle chain theories postulating simple biomechanical coupling of neck and jaw muscles. Co-contractions of neck and masticatory muscles may instead occur as a result of complex neurophysiological interactions. © 2018 John Wiley & Sons Ltd.

Analysis of scapular muscle EMG activity in patients with idiopathic neck pain: a systematic review.

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Castelein, Birgit; Cools, Ann; Bostyn, Emma; Delemarre, Jolien; Lemahieu, Trees; Cagnie, Barbara

2015-04-01

It is proposed that altered scapular muscle function can contribute to abnormal loading of the cervical spine. However, it is not clear if patients with idiopathic neck pain show altered activity of the scapular muscles. The aim of this paper was to systematically review the literature regarding the differences or similarities in scapular muscle activity, measured by electromyography ( = EMG), between patients with chronic idiopathic neck pain compared to pain-free controls. Case-control (neck pain/healthy) studies investigating scapular muscle EMG activity (amplitude, timing and fatigue parameters) were searched in Pubmed and Web of Science. 25 articles were included in the systematic review. During rest and activities below shoulder height, no clear differences in mean Upper Trapezius ( = UT) EMG activity exist between patients with idiopathic neck pain and a healthy control group. During overhead activities, no conclusion for scapular EMG amplitude can be drawn as a large variation of results were reported. Adaptation strategies during overhead tasks are not the same between studies. Only one study investigated timing of the scapular muscles and found a delayed onset and shorter duration of the SA during elevation in patients with idiopathic neck pain. For scapular muscle fatigue, no definite conclusions can be made as a wide variation and conflicting results are reported. Further high quality EMG research on scapular muscles (broader than the UT) is necessary to understand/draw conclusions on how scapular muscles react in the presence of idiopathic neck pain. Copyright © 2015 Elsevier Ltd. All rights reserved.

Increased sternocleidomastoid, but not trapezius, muscle activity in response to increased chewing load.

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Häggman-Henrikson, Birgitta; Nordh, Erik; Eriksson, Per-Olof

2013-10-01

Previous findings, during chewing, that boluses of larger size and harder texture result in larger amplitudes of both mandibular and head-neck movements suggest a relationship between increased chewing load and incremental recruitment of jaw and neck muscles. The present report evaluated jaw (masseter and digastric) and neck [sternocleidomastoid (SCM) and trapezius] muscle activity during the chewing of test foods of different sizes and textures by 10 healthy subjects. Muscle activity was recorded by surface electromyography and simultaneous mandibular and head movements were recorded using an optoelectronic technique. Each subject performed continuous jaw-opening/jaw-closing movements whilst chewing small and large boluses of chewing gum and rubber silicone (Optosil). For jaw opening/jaw closing without a bolus, SCM activity was recorded for jaw opening concomitantly with digastric activity. During chewing, SCM activity was recorded for jaw closing concomitantly with masseter activity. Trapezius activity was present in some, but not all, cycles. For the masseter and SCM muscles, higher activity was seen with larger test foods, suggesting increased demand and recruitment of these muscles in response to an increased chewing load. This result reinforces the previous notion of a close functional connection between the jaw and the neck motor systems in jaw actions and has scientific and clinical significance for studying jaw function and dysfunction. © 2013 Eur J Oral Sci.

Influence of experimental occlusal discrepancy on masticatory muscle activity during clenching.

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Baba, K; Ai, M; Mizutani, H; Enosawa, S

1996-01-01

The influence of the experimental occlusal discrepancy on masticatory muscle activity was investigated on 12 subjects. Specially designed occlusal interferences were fabricated and various occlusal states were simulated with their aid. Subjects were asked to carry out eccentric clenching efforts and electromyographic activity of the masseter plus the anterior and posterior temporal muscles was measured. When compared with clenching on the unaltered natural dentition, clenching on the experimental interferences resulted in distinct patterns in the jaw elevator muscles, and the most characteristic change was observed when clenching effort was exerted on the experimental non-working side interference. Electromyographic activity in the anterior and posterior temporal muscles was decreased on the working side and increased on the non-working side and originally unilateral activity pattern with clear dominance on the working side was altered to a bilateral pattern, while that of the masseter muscles remained uninfluenced. Resultant bilateral activity in the anterior and posterior temporal muscles is thought to cause a superior movement of the working side condyle and an inferior movement of the non-working side condyle.

Size and symmetry of trunk muscles in ballet dancers with and without low back pain.

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Gildea, Jan E; Hides, Julie A; Hodges, Paul W

2013-08-01

Cross-sectional, observational study. To investigate the cross-sectional area (CSA) of trunk muscles in professional ballet dancers with and without low back pain (LBP). LBP is the most prevalent chronic injury in classical ballet dancers. Research on nondancers has found changes in trunk muscle size and symmetry to be associated with LBP. There are no studies that examine these changes in ballet dancers. Magnetic resonance imaging was performed in 14 male and 17 female dancers. The CSAs of 4 muscles (multifidus, lumbar erector spinae, psoas, and quadratus lumborum) were measured and compared among 3 groups of dancers: those without LBP or hip pain (n = 8), those with LBP only (n = 13), and those with both hip-region pain and LBP (n = 10). Dancers with no pain had larger multifidus muscles compared to those with LBP at L3-5 (P.05). The CSAs of the other muscles did not differ between groups. The psoas (Pballet dancers, LBP and hip-region pain and LBP are associated with a smaller CSA of the multifidus but not the erector spinae, psoas, or quadratus lumborum muscles.

Ergonomic factors that cause the presence of pain muscle in students of dentistry.

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Diaz-Caballero, Antonio-José; Gómez-Palencia, Isabel-Patricia; Díaz-Cárdenas, Shyrley

2010-11-01

To identify the ergonomic factors and the presence of muscular pain in dental students of VIII, IX, X semesters presently practicing at the clinics of the College of Dentistry of university of Cartagena, Colombia, South America. This is a descriptive study carried out in dental students of the VIII, IX, and X semesters which were undergoing clinical practice at the College of Dentistry of University of Cartagena. A convenience sample of 83 students who met the inclusion criteria was taken and those who agreed to participate signed an informed consent. Data collection was obtained by means of a structured questionnaire for ergonomic factors and the presence of pain was identified palpating the muscles object of the study by a physical therapist. The variables evaluated were: presence of pain, affected muscles, affected zones, gender, postures and work environment. The adoption of inadequate postures such as exaggerated flexions or cervical torsions could generate a higher frequency of muscular pain in dental students. The approximating muscle of the thumb showed 11% frequency of pain. The presence of muscular pain was higher for the female group participating in this study. Dentists are prone, since the beginning of their clinical practice as students, to lesions of the skeletal muscle system due to the clinical exercise of the profession, being the most common, muscle pain in the back, neck, shoulders and hands. This would imply initiating an occupational health program promoting healthy lifestyles in their academic environment and their future professional life, at the beginning of their clinical practice in dental school.

Muscle Power Is an Independent Determinant of Pain and Quality of Life in Knee Osteoarthritis.

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Reid, Kieran F; Price, Lori Lyn; Harvey, William F; Driban, Jeffrey B; Hau, Cynthia; Fielding, Roger A; Wang, Chenchen

2015-12-01

This study examined the relationships between leg muscle strength, power, and perceived disease severity in subjects with knee osteoarthritis (OA) in order to determine whether dynamic leg extensor muscle power would be associated with pain and quality of life in knee OA. Baseline data on 190 subjects with knee OA (mean ± SD age 60.2 ± 10.4 years, body mass index 32.7 ± 7.2 kg/m(2) ) were obtained from a randomized controlled trial. Knee pain was measured using the Western Ontario and McMaster Universities Osteoarthritis Index, and health-related quality of life was assessed using the Short Form 36 (SF-36). One-repetition maximum (1RM) strength was assessed using the bilateral leg press, and peak muscle power was measured during 5 maximum voluntary velocity repetitions at 40% and 70% of 1RM. In univariate analysis, greater muscle power was significantly associated with pain (r = -0.17, P power was a significant independent predictor of pain (P ≤ 0.05) and PCS scores (P ≤ 0.04). However, muscle strength was not an independent determinant of pain or quality of life (P ≥ 0.06). Muscle power is an independent determinant of pain and quality of life in knee OA. Compared to strength, muscle power may be a more clinically important measure of muscle function within this population. New trials to systematically examine the impact of muscle power training interventions on disease severity in knee OA are particularly warranted. © 2015, American College of Rheumatology.

Experimental knee pain impairs submaximal force steadiness in isometric, eccentric, and concentric muscle actions.

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Rice, David A; McNair, Peter J; Lewis, Gwyn N; Mannion, Jamie

2015-09-12

Populations with knee joint damage, including arthritis, have noted impairments in the regulation of submaximal muscle force. It is difficult to determine the exact cause of such impairments given the joint pathology and associated neuromuscular adaptations. Experimental pain models that have been used to isolate the effects of pain on muscle force regulation have shown impaired force steadiness during acute pain. However, few studies have examined force regulation during dynamic contractions, and these findings have been inconsistent. The goal of the current study was to examine the effect of experimental knee joint pain on submaximal quadriceps force regulation during isometric and dynamic contractions. The study involved fifteen healthy participants. Participants were seated in an isokinetic dynamometer. Knee extensor force matching tasks were completed in isometric, eccentric, and concentric muscle contraction conditions. The target force was set to 10 % of maximum for each contraction type. Hypertonic saline was then injected into the infrapatella fat pad to generate acute joint pain. The force matching tasks were repeated during pain and once more 5 min after pain had subsided. Hypertonic saline resulted in knee pain with an average peak pain rating of 5.5 ± 2.1 (0-10 scale) that lasted for 18 ± 4 mins. Force steadiness significantly reduced during pain across all three muscle contraction conditions. There was a trend to increased force matching error during pain but this was not significant. Experimental knee pain leads to impaired quadriceps force steadiness during isometric, eccentric, and concentric contractions, providing further evidence that joint pain directly affects motor performance. Given the established relationship between submaximal muscle force steadiness and function, such an effect may be detrimental to the performance of tasks in daily life. In order to restore motor performance in people with painful arthritic conditions of the

Jaw-muscle fiber architecture in tufted capuchins favors generating relatively large muscle forces without compromising jaw gape

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Taylor, Andrea B.; Vinyard, Christopher J.

2009-01-01

Cebus apella is renowned for its dietary flexibility and capacity to exploit hard and tough objects. Cebus apella differs from other capuchins in displaying a suite of craniodental features that have been functionally and adaptively linked to their feeding behavior, particularly the generation and dissipation of relatively large jaw forces. We compared fiber architecture of the masseter and temporalis muscles between the tufted capuchin (C. apella; n = 12 ) and two “untufted” capuchins (C. capuchinus, n = 3; C. albifrons, n = 5). These three species share broadly similar diets, but tufted capuchins occasionally exploit mechanically challenging tissues. We tested the hypothesis that C. apella exhibits architectural properties of their jaw muscles that facilitate relatively large forces, including relatively greater physiologic cross-sectional areas (PCSA), more pinnate fibers, and lower ratios of mass to tetanic tension (Mass/P0). Results show some evidence supporting these predictions, as C. apella has relatively greater superficial masseter, whole masseter, and temporalis PCSAs, significantly so only for the temporalis following Bonferroni adjustment. Capuchins did not differ in pinnation angle or Mass/P0. As an architectural trade-off between maximizing muscle force and muscle excursion/contraction velocity, we also tested the hypothesis that C. apella exhibits relatively shorter muscle fibers. Contrary to our prediction, there are no significant differences in relative fiber lengths between tufted and untufted capuchins. Therefore, we attribute the relatively greater PCSAs in C. apella primarily to their larger muscle masses. These findings suggest that relatively large jaw-muscle PCSAs can be added to the suite of masticatory features that have been functionally linked to the exploitation of a more resistant diet by C. apella. By enlarging jaw-muscle mass to increase PCSA, rather than reducing fiber lengths and increasing pinnation, tufted capuchins appear

Function and structure of the deep cervical extensor muscles in patients with neck pain.

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Schomacher, Jochen; Falla, Deborah

2013-10-01

The deep cervical extensors are anatomically able to control segmental movements of the cervical spine in concert with the deep cervical flexors. Several investigations have confirmed changes in cervical flexor muscle control in patients with neck pain and as a result, effective evidence-based therapeutic exercises have been developed to address such dysfunctions. However, knowledge on how the deep extensor muscles behave in patients with neck pain disorders is scare. Structural changes such as higher concentration of fat within the muscle, variable cross-sectional area and higher proportions of type II fibres have been observed in the deep cervical extensors of patients with neck pain compared to healthy controls. These findings suggest that the behaviour of the deep extensors may be altered in patients with neck pain. Consistent with this hypothesis, a recent series of studies confirm that patients display reduced activation of the deep cervical extensors as well as less defined activation patterns. This article provides an overview of the various different structural and functional changes in the deep neck extensor muscles documented in patients with neck pain. Relevant recommendations for the management of muscle dysfunction in patients with neck pain are presented. Copyright © 2013 Elsevier Ltd. All rights reserved.

Repeated tongue lift movement induces neuroplasticity in corticomotor control of tongue and jaw muscles in humans.

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Komoda, Yoshihiro; Iida, Takashi; Kothari, Mohit; Komiyama, Osamu; Baad-Hansen, Lene; Kawara, Misao; Sessle, Barry; Svensson, Peter

2015-11-19

This study investigated the effect of repeated tongue lift training (TLT) on the excitability of the corticomotor representation of the human tongue and jaw musculature. Sixteen participants performed three series of TLT for 41 min on each of 5 consecutive days. Each TLT series consisted of two pressure levels (5 kPa and 10 kPa). All participants underwent transcranial magnetic stimulation (TMS) and electromyographic (EMG) recordings of motor evoked potentials (MEPs) in four sessions: (1) before TLT on Day 1 (baseline), (2) after TLT on Day 1, (3) before TLT on Day 5, and (4) after TLT on Day 5. EMG recordings from the left and right tongue dorsum and masseter muscles were made at three pressure levels (5 kPa, 10 kPa, 100% tongue lift), and tongue, masseter, and first dorsal interosseous (FDI) MEPs were measured. There were no significant day-to-day differences in the tongue pressure during maximum voluntary contractions. The amplitudes and thresholds of tongue and masseter MEPs after TLT on Day 5 were respectively higher and lower than before TLT on Day 1 (P<0.005), and there was also a significant increase in tongue and masseter MEP areas; no significant changes occurred in MEP onset latencies. FDI MEP parameters (amplitude, threshold, area, latency) were not significantly different between the four sessions. Our findings suggest that repeated TLT can trigger neuroplasticity reflected in increased excitability of the corticomotor representation of not only the tongue muscles but also the masseter muscles. Copyright © 2015. Published by Elsevier B.V.

Specific proteins of the trapezius muscle correlate with pain intensity and sensitivity – an explorative multivariate proteomic study of the trapezius muscle in women with chronic widespread pain

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Olausson P

2016-06-01

Full Text Available Patrik Olausson, Bijar Ghafouri, Nazdar Ghafouri, Björn Gerdle Pain and Rehabilitation Centre, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden Abstract: Chronic widespread pain (CWP including fibromyalgia syndrome (FMS has a high prevalence and is associated with prominent negative consequences. CWP/FMS exhibits morphological and functional alterations in the central nervous system. The importance of peripheral factors for maintaining the central alterations are under debate. In this study, the proteins from biopsies of the trapezius muscle from 18 female CWP/FMS patients and 19 healthy female controls were analyzed. Pain intensity and pressure pain thresholds (PPT over the trapezius muscles were registered. Twelve proteins representing five different groups of proteins were important regressors of pain intensity in CWP/FMS (R2=0.99; P<0.001. In the regression of PPT in CWP/FMS, it was found that 16 proteins representing six groups of proteins were significant regressors (R2=0.95, P<0.05. Many of the important proteins were stress and inflammation proteins, enzymes involved in metabolic pathways, and proteins associated with muscle damage, myopathies, and muscle recovery. The altered expression of these proteins may reflect both direct and indirect nociceptive/inflammatory processes as well as secondary changes. The relative importance of the identified proteins and central alterations in CWP need to be investigated in future research. Data from this and the previous study concerning the same cohorts give support to the suggestion that peripheral factors are of importance for maintaining pain aspects in CWP/FMS. Keywords: chronic widespread pain, proteomics, biomarkers, multivariate data analysis, pain threshold, numeric rating scale

The effect of fear of movement on muscle activation in posttraumatic neck pain disability

NARCIS (Netherlands)

Nederhand, Marcus Johannes; Hermens, Hermanus J.; IJzerman, Maarten Joost; Groothuis-Oudshoorn, Catharina Gerarda Maria; Turk, Dennis C.

Studies using surface electromyography have demonstrated a reorganization of muscle activation patterns of the neck and shoulder muscles in patients with posttraumatic neck pain disability. The neurophysiologically oriented "pain adaptation" model explains this reorganization as a useful adaptation

Clinical features in patients with chronic muscle pain--with special reference to fibromyalgia

DEFF Research Database (Denmark)

Jacobsen, Søren; Petersen, I S; Danneskiold-Samsøe, B

1993-01-01

was not excessive and seemed appropriate compared to the other patient groups. Effects of various biases and classification criteria on the results of fibromyalgia studies are discussed. The characteristic features of fibromyalgia, its stability when diagnosed and the promotion of research and patient management......Clinical characteristics were studied in patients with chronic muscle pain, divided into three groups according to the characteristics of their pain; "fibromyalgia" (n = 23), "widespread muscle pain" (n = 21), and "regional muscle pain" (n = 28). Typical fibromyalgia features were also seen...... in the other groups of patients, but not to the same extent. In particular, sleep disturbance, subjective swelling, cold and exercise intolerance and low self-reported physical performance were significantly related to fibromyalgia. The major components of fibromyalgia were not wholly different compared...

Delayed onset muscle soreness: No pain, no gain? The truth behind ...

African Journals Online (AJOL)

Delayed onset muscle soreness (DOMS) is muscle pain and stiffness that develops ... limited success in reducing the symptoms.1,4-6 The DOMS phenomenon ... Nutritional supplementation (antioxidants and L-carnitine) shows promise, but ...

The use of surface electromyography as a tool in differentiating temporomandibular disorders from neck disorders.

Science.gov (United States)

Ferrario, Virgilio F; Tartaglia, Gianluca M; Luraghi, Francesca E; Sforza, Chiarella

2007-11-01

The aim of this study was to assess the electromyographic characteristics of the masticatory muscles (masseter and temporalis) of patients with either "temporomandibular joint disorder" or "neck pain". Surface electromyography of the right and left masseter and temporalis muscles was performed during maximum teeth clenching in 38 patients aged 21-67 years who had either (a) temporomandibular joint disorder (24 patients); (b) "neck pain" (13 patients). Ninety-five control, healthy subjects were also examined. During clenching, standardized total muscle activities (electromyographic potentials over time) were significantly different in the three groups: 75 microV/microVs% in the temporomandibular joint disorder patients, 124 microV/microVs% in the neck pain patients, and 95 microV/microVs% in the control subjects (analysis of variance, Ptemporomandibular joint disorder patients also had significantly (Pneck pain patients (87%) or control subjects (92%). A linear discriminant function analysis allowed a significant separation between the two patient groups, with a single patient error of 18.2%. Surface electromyographic analysis during clenching allowed to differentiate between patients with a temporomandibular joint disorder and patients with a neck pain problem.

Uso de toxina botulínica para tratamiento de la hipertrofía del músculo masetero Use of botulinum toxin for treatment of hypetrophy of the masseter muscle

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F. González Magaña

2012-09-01

Full Text Available Definimos la hipertrofia del músculo masetero como el crecimiento excesivo de la masa muscular de dicho músculo, de presentación subclínica y de etiología multifactorial. Presenta una incidencia entre los 20 a 40 años sin predilección de sexo. Desde que en 1880 Legg la describiera por primera vez, se han intentado múltiples tratamientos, desde los médicos hasta los quirúrgicos, siendo el tratamiento con toxina botulínica el de mayor aceptación en la actualidad. El objetivo del presente artículo es realizar una revisión bibliográfica y proveer una herramienta para el médico que se enfrente a la hipertrofia del músculo masetero, además de presentar un caso clínico unilateral y la técnica empleada para su tratamiento. Como método diagnóstico en el paciente empleamos TAC de cráneo y macizo facial con cortes finos a 1 mm, así como de la región maseterina y aplicamos toxina botulínica de acuerdo a la zona de seguridad propuesta por Nam-Ho Kim y en base a los puntos anatómicos que indica el mismo protocolo, a dosis de 50 U en intervalos de 3 meses. Empleamos también TAC postoperatorio como medio de evaluación del resultado. Los tratamientos médicos con toxina botulínica son variables en sus dosis, aplicaciones y técnicas, así como en los diferentes productos disponibles en el mercado. En nuestro caso, el resultado fue clínicamente satisfactorio, cubriendo en su totalidad las expectativas del paciente. Proponemos que la protocolización del paciente, las dosis adecuadas, el tiempo entre aplicaciones y los sitios anatómicos correctos de inyección, llevan a la corrección de la hipertrofia del músculo masetero.Masseter muscle hypertrophy is an overgrowth of muscle mass with subclinical presentation and multifactorial etiology, with an incidence between 20 to 40 years and without sex predilection. In 1880 Legg describes this pathology for the first time and since then have been reported and attempted to formally

Examination of contraction-induced muscle pain as a behavioral correlate of physical activity in women with and without fibromyalgia.

Science.gov (United States)

Umeda, Masataka; Corbin, Lisa W; Maluf, Katrina S

2015-01-01

This study aimed to compare muscle pain intensity during a sustained isometric contraction in women with and without fibromyalgia (FM), and examine the association between muscle pain and self-reported levels of physical activity. Fourteen women with FM and 14 healthy women completed the study, where muscle pain ratings (MPRs) were obtained every 30 s during a 3 min isometric handgrip task at 25% maximal strength, and self-reported physical activity was quantified using the Baecke Physical Activity Questionnaire. Women with FM were less physically active than healthy controls. During the isometric contraction, MPR progressively increased in both groups at a comparable rate, but women with FM generally reported a greater intensity of muscle pain than healthy controls. Among all women, average MPR scores were inversely associated with self-reported physical activity levels. Women with FM exhibit augmented muscle pain during isometric contractions and reduced physical activity than healthy controls. Furthermore, contraction-induced muscle pain is inversely associated with physical activity levels. These observations suggest that augmented muscle pain may serve as a behavioral correlate of reduced physical activity in women with FM. Implications for Rehabilitation Women with fibromyalgia experience a greater intensity of localized muscle pain in a contracting muscle compared to healthy women. The intensity of pain during muscle contraction is inversely associated with the amount of physical activity in women with and without fibromyalgia. Future studies should determine whether exercise adherence can be improved by considering the relationship between contraction-induced muscle pain and participation in routine physical activity.

The correlation between surface electromyography and bite force of mastication muscles in Asian young adults.

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Yen, Cheng-I; Mao, Shih-Hsuan; Chen, Chih-Hao; Chen, Chien-Tzung; Lee, Ming-Yih

2015-05-01

Mastication function is related to mandible movement, muscle strength, and bite force. No standard device for measuring bite force has been developed. A linear relationship between electromyographic activity and bite force has been reported by several investigators, but data on the reliability of this relationship remain limited in Asian young adults. The purpose of this study was to develop a clinically applicable, reliable, quantitative, and noninvasive system to measure the kinetic mastication function and observe the correlation between surface electromyography (sEMG) and bite force. The study group consisted of 41 young healthy adults (24 men and 17 women). Surface electromyography was used to evaluate bilateral temporalis and masseter muscle activities, and an occlusal bite force system was used concurrently to measure the bite force during maximal voluntary biting. Bilateral symmetry was compared, and the correlation between EMG and bite force was calculated. The sEMG signals were 107.7±55.0 μV and 106.0±56.0 μV (P=0.699) on right and left temporalis muscles and 183.7±86.2 μV and 194.8±94.3 μV (P=0.121) on right and left masseter muscles, respectively. The bite force was 5.0±3.2 kg on the right side and 5.7±4.0 kg on the left side (P=0.974). A positive correlation between sEMG and bite force was observed. The correlation coefficient between the temporalis muscle and bite force was 0.512, and that between the masseter muscle and bite force was 0.360. No significant difference between the bilateral electromyographic activities of the temporalis and masseter muscles and bilateral bite force was observed in young healthy adults in Taiwan. A positive correlation between sEMG signals and bite force was noted. By combining sEMG and bite force, we developed a clinically applicable, quantitative, reliable, and noninvasive system for evaluating mastication function by using characteristics of biofeedback.

Deep pain sensitivity is correlated with oral-health-related quality of life but not with prosthetic factors in complete denture wearers

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Yuri Martins COSTA

2015-12-01

Full Text Available ABSTRACT Low pressure Pain Threshold (PPT is considered a risk factor for Temporomandibular Disorders (TMD and is influenced by psychological variables. Objectives To correlate deep pain sensitivity of masticatory muscles with prosthetic factors and Oral-Health-Related Quality of Life (OHRQoL in completely edentulous subjects. Material and Methods A total of 29 complete denture wearers were recruited. The variables were: a Pressure Pain Threshold (PPT of the masseter and temporalis; b retention, stability, and tooth wear of dentures; c Vertical Dimension of Occlusion (VDO; d Oral Health Impact Profile (OHIP adapted to orofacial pain. The Kolmogorov-Smirnov test, the Pearson Product-Moment correlation coefficient, the Spearman Rank correlation coefficient, the Point-Biserial correlation coefficient, and the Bonferroni correction (α=1% were applied to the data. Results The mean age (standard deviation of the participants was of 70.1 years (9.5 and 82% of them were females. There were no significant correlations with prosthetic factors, but significant negative correlations were found between the OHIP and the PPT of the anterior temporalis (r=-0.50, 95% CI-0.73 to 0.17, p=0.005. Discussion The deep pain sensitivity of masticatory muscles in complete dentures wearers is associated with OHRQoL, but not with prosthetic factors.

Deep pain sensitivity is correlated with oral-health-related quality of life but not with prosthetic factors in complete denture wearers

Science.gov (United States)

COSTA, Yuri Martins; PORPORATTI, André Luís; HILGENBERG-SYDNEY, Priscila Brenner; BONJARDIM, Leonardo Rigoldi; CONTI, Paulo César Rodrigues

2015-01-01

ABSTRACT Low pressure Pain Threshold (PPT) is considered a risk factor for Temporomandibular Disorders (TMD) and is influenced by psychological variables. Objectives To correlate deep pain sensitivity of masticatory muscles with prosthetic factors and Oral-Health-Related Quality of Life (OHRQoL) in completely edentulous subjects. Material and Methods A total of 29 complete denture wearers were recruited. The variables were: a) Pressure Pain Threshold (PPT) of the masseter and temporalis; b) retention, stability, and tooth wear of dentures; c) Vertical Dimension of Occlusion (VDO); d) Oral Health Impact Profile (OHIP) adapted to orofacial pain. The Kolmogorov-Smirnov test, the Pearson Product-Moment correlation coefficient, the Spearman Rank correlation coefficient, the Point-Biserial correlation coefficient, and the Bonferroni correction (α=1%) were applied to the data. Results The mean age (standard deviation) of the participants was of 70.1 years (9.5) and 82% of them were females. There were no significant correlations with prosthetic factors, but significant negative correlations were found between the OHIP and the PPT of the anterior temporalis (r=-0.50, 95% CI-0.73 to 0.17, p=0.005). Discussion The deep pain sensitivity of masticatory muscles in complete dentures wearers is associated with OHRQoL, but not with prosthetic factors. PMID:26814457

Isolated unilateral temporalis muscle hypertrophy in a child: a case report with literature review

OpenAIRE

Ranasinghe, Jagath C.; Wickramasinghe, Chandani; Rodrigo, Ganganath

2018-01-01

Background Temporalis muscle hypertrophy is a rare entity of masticatory muscle hypertrophy. All types of masticatory muscle hypertrophies have been documented of which temporalis muscle hypertrophy is one. Temporalis muscle hypertrophy is most commonly bilateral and usually associated with other types of masticatory muscles hypertrophy such as masseter or pterygoid hypertrophy. However, isolated unilateral temporalis muscle hypertrophy is extremely rare and only 9 cases have been reported to...

Cortical Silent Period Reveals Differences Between Adductor Spasmodic Dysphonia and Muscle Tension Dysphonia.

Science.gov (United States)

Samargia, Sharyl; Schmidt, Rebekah; Kimberley, Teresa Jacobson

2016-03-01

The pathophysiology of adductor spasmodic dysphonia (AdSD), like other focal dystonias, is largely unknown. The purposes of this study were to determine (a) cortical excitability differences between AdSD, muscle tension dysphonia (MTD), and healthy controls; (b) distribution of potential differences in cranial or skeletal muscle; and (c) if cortical excitability measures assist in the differential diagnosis of AdSD and MTD. Ten participants with adductor spasmodic dysphonia, 8 with muscle tension dysphonia, and 10 healthy controls received single and paired pulse transcranial magnetic stimulation (TMS) to the primary motor cortex contralateral to tested muscles, first dorsal interosseus (FDI), and masseter. We tested the hypothesis that cortical excitability measures in AdSD would be significantly different from those in MTD and healthy controls. In addition, we hypothesized that there would be a correlation between cortical excitability measures and clinical voice severity in AdSD. Cortical silent period duration in masseter and FDI was significantly shorter in AdSD than MTD and healthy controls. Other measures failed to demonstrate differences. There are differences in cortical excitability between AdSD, MTD, and healthy controls. These differences in the cortical measure of both the FDI and masseter muscles in AdSD suggest widespread dysfunction of the GABAB mechanism may be a pathophysiologic feature of AdSD, similar to other forms of focal dystonia. Further exploration of the use of TMS to assist in the differential diagnosis of AdSD and MTD is warranted. © The Author(s) 2015.

Low-level laser therapy in the treatment of muscle-skelet pain in patients affected by temporo-mandibular disorders.

Science.gov (United States)

Basili, M; Barlattani, A; Venditti, A; Bollero, P

2017-01-01

The purpose of the study is to evaluate the effectiveness of Low-Level Laser Therapy in reducing joint and muscle pain in patients with acute and chronic temporomandibular dysfunction. The study was conducted on a sample of 180 patients. The sample was divided into two groups according to the time of onset of the disease: acute TMD ( 6 months). The treatment for all patients provided for the irradiation with Diode Laser Wiser Doctor Smile with tip plane wave at wavelength of 830 nm, continuous beam to 40nW diameter and radius of 6 mm. The irradiated areas were the joint area, temporal, masseter and pterygoid. The irradiation time for each zone was 60s.The protocol adopted consisted of two weekly treatment for six weeks. Pain assessment was performed using the Visual Analog Scale (VAS), in which different scores (s) depending accused of pain by the patient: s0 no pain, s1-3 mild pain, s4-6 moderate pain, s7-9 severe pain and s10 excessive pain. The pain monitoring was performed before treatment, after 15 days and after one month. The sample included 80 patients with acute TMD and 100 with chronic TMD. The sample belonging to acute TMD group before treatment, was distributed as follows: 0% in s0; 12,5% in s1-3; 31.3% in s4-6; 53.6% in s7-9 and 2.5% in s10. After 15 days the distribution was was as follows: 6.25% in s0; 47.5% in s1-3; 20% in s4-6; 26.3% in s7-9 and 0% in s10. After 30 days the sample was well distributed: 35% in s0; 45% in 1-3; 10% in s4-6; 10% in s7-9 and 0% in s10. The sample belonging to the chronic TMD group, at time zero, was as follows: 0% at s0; 48% in S1-3; 35% in s4-6; 15% in s7-9 and 2% in s10. After 15 days the distribution was: 29% in s0; 28% in S1-3; 33% in s4-6; 10% in s7-9 and 0% in s10. After 30 days the sample was well distributed: 45% in s0; 36% in S1-3; 15% in s4-6; 4% in s7-9 and 0% in s10. The Low-Level-Laser-Therapy is a valuable tool that can significantly decrease the perception of pain in patients with temporomandibular joint

Experimental knee joint pain during strength training and muscle strength gain in healthy subjects: a randomized controlled trial.

Science.gov (United States)

Sørensen, T J; Langberg, H; Hodges, P W; Bliddal, H; Henriksen, M

2012-01-01

Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals. Twenty-seven healthy untrained volunteers participated in a randomized controlled trial of quadriceps strengthening (3 times per week for 8 weeks). Participants were randomized to perform resistance training either during pain induced by injections of painful hypertonic saline (pain group, n = 13) or during a nonpainful control condition with injection of isotonic saline (control group, n = 14) into the infrapatellar fat pad. The primary outcome measure was change in maximal isokinetic muscle strength in knee extension/flexion (60, 120, and 180 degrees/second). The group who exercised with pain had a significantly larger improvement in isokinetic muscle strength at all angular velocities of knee extension compared to the control group. In knee flexion there were improvements in isokinetic muscle strength in both groups with no between-group differences. Experimental knee joint pain improved the training-induced gain in muscle strength following 8 weeks of quadriceps training. It remains to be studied whether knee joint pain has a positive effect on strength gain in patients with knee pathology. Copyright © 2012 by the American College of Rheumatology.

Structural Changes of Lumbar Muscles in Non-specific Low Back Pain: A Systematic Review.

Science.gov (United States)

Goubert, Dorien; Oosterwijck, Jessica Van; Meeus, Mira; Danneels, Lieven

2016-01-01

Lumbar muscle dysfunction due to pain might be related to altered lumbar muscle structure. Macroscopically, muscle degeneration in low back pain (LBP) is characterized by a decrease in cross-sectional area and an increase in fat infiltration in the lumbar paraspinal muscles. In addition microscopic changes, such as changes in fiber distribution, might occur. Inconsistencies in results from different studies make it difficult to draw firm conclusions on which structural changes are present in the different types of non-specific LBP. Insights regarding structural muscle alterations in LBP are, however, important for prevention and treatment of non-specific LBP. The goal of this article is to review which macro- and/or microscopic structural alterations of the lumbar muscles occur in case of non-specific chronic low back pain (CLBP), recurrent low back pain (RLBP), and acute low back pain (ALBP). Systematic review. All selected studies were case-control studies. A systematic literature search was conducted in the databases PubMed and Web of Science. Only full texts of original studies regarding structural alterations (atrophy, fat infiltration, and fiber type distribution) in lumbar muscles of patients with non-specific LBP compared to healthy controls were included. All included articles were scored on methodological quality. Fifteen studies were found eligible after screening title, abstract, and full text for inclusion and exclusion criteria. In CLBP, moderate evidence of atrophy was found in the multifidus; whereas, results in the paraspinal and the erector spinae muscle remain inconclusive. Also moderate evidence occurred in RLBP and ALBP, where no atrophy was shown in any lumbar muscle. Conflicting results were seen in undefined LBP groups. Results concerning fat infiltration were inconsistent in CLBP. On the other hand, there is moderate evidence in RLBP that fat infiltration does not occur, although a larger muscle fat index was found in the erector spinae

Characteristics of masticatory muscles in children with unilateral posterior crossbite

Directory of Open Access Journals (Sweden)

Annicele da Silva Andrade

2010-06-01

Full Text Available The aim of this study was to detect possible differences in the EMG (electromiography activity, chewing rate (CR, cycle duration (CD and preferred chewing side (PCS between children with and without unilateral posterior crossbite. Thirty-seven children aged from 7 to 10 years were selected from the clinic of the Department of Pediatric Dentistry, Piracicaba Dental School, Brazil, and divided into two groups: unilateral posterior crossbite (UPCB group, n = 17, and normal occlusion (NOccl group, n = 20. The PCS was determined using a visual spot-checking method. The EMG activity was recorded during mastication, and two chewing sequences of 20 s were evaluated to establish each subject's CR (cycles/sec and CD. UPCB and NOccl groups did not have a PCS. The EMG activity and the cycle characteristics did not differ between the groups. The correlations between CD, CR and EMG activity were statistically significant for the masseter and anterior temporalis muscles only in the NOccl group, in which there was also a significant correlation between the EMG activity of masseter and anterior temporalis. In conclusion, these findings suggest that although children with and without UPCB presented a bilateral masticatory pattern with similar CR and CD, balanced EMG activity of masseter and anterior temporalis muscles was observed only in the NOccl group. These results indicate that in children, UPCB can alter the coordination of masticatory muscles during mastication.

MR imaging of sports-related muscle pain

International Nuclear Information System (INIS)

Fleckenstein, J.L.; Weatherall, P.T.; Parkey, R.W.; Peshock, R.M.

1988-01-01

Muscle pain following exercise occurs acutely or after a significant delay. MR imaging of the lower extremities was performed in acute strains (N=3); runners after a 30-km marathon (N=10); and sedentary subjects, 3-5 days after brief ankle plantarflexion (N=5). Serum creatine kinase (CK) levels were determined in groups 2 and 3. Abnormal signal intensity was evident in all groups. The increase in CK level was associated in time with onset of signal increase in group 3. MR imaging is useful in defining the distribution, extent, and natural history of exercise-induced muscle injury

Efficacy of low-level laser therapy on orofacial pain: A literature review

Directory of Open Access Journals (Sweden)

Haleh Zokaee

2018-01-01

Full Text Available Low-level laser therapy (LLLT is a therapeutic approach to treat orofacial pain using a 600–1000 nm laser with a <500 mW power. The efficacy of LLLT is due to the chemical reactions causing an anti-inflammatory and analgesic effect on the affected regions. The aim of this study is to review the effects of low-level laser application on orofacial pain in the English articles released since 2017. Our search keywords were 'low-level laser therapy, temporomandibular disease (TMD, mucositis and orofacial pain'. The most relevant papers were clinical trial, review and meta-analysis articles. 26 out of 243 searched articles were selected from PubMed, Google Scholar and Science Direct and reviewed. Most of the studies reported the positive role of LLLT on orofacial pain relief regardless of their variable procedures; however, the exact mechanism of action still remains unclear. Some studies indicated that LLLT has significantly reduced pain, reduceamount of clicking and both masseter and temporal muscles activityin TMD. As an overall result, it is concluded that LLLT can be served as a therapeutic method for myofascial pain, mucositis and temporomandibular joint disorders and this is due to its analgesic features.

Histomorphometrical analysis of the influence of soft diet on masticatory muscle development in the muscular dystrophic mouse

DEFF Research Database (Denmark)

Vilmann, H; Kirkeby, S; Kronborg, D

1990-01-01

The known difference in the severity of dystrophy between the masseter and the digastric muscle of the mouse (dy/dy C57BL/J6) may be attributed to the differences in muscle work load. This possibility was tested by subjecting 3-week-old mice (normal and dystrophic) to a soft diet for 4 weeks....... Microscopic examination of haematoxylin-eosin stained sections of these muscles showed that the fibre size dispersion (a measure of disease severity) decreased slightly but significantly in the masseters of mice on a soft diet. It was thus possible to improve the condition of dystrophic masticatory muscles...... by changing their function. Body weight curves measured during the experimental period suggest that the dystrophic mice may have been under weight because of malnutrition due to lack of sufficient masticatory power....

[Bruxism, temporo-mandibular dysfunction and botulinum toxin].

Science.gov (United States)

Chikhani, L; Dichamp, J

2003-07-01

Tooth grinding and tooth clenching are unvoluntary mainly nocturnal habits that result in an hypertrophy of masseter and temporalis muscles with an unbalance between opening and closing muscles of the jaw and lead to an alteration of mandibular condyles movements and to hyper pressure in the temporo-mandibular joints (TMJ) which can generate severe pain. Intra muscular injections of botulinum toxin permit to restablish the balance between closing and opening muscles, to relieve pain, to treat masseteric hypertrophy with improvement of face outline and to recover a normal cinetic of temporo-mandibular joints. Moreover, botulinum toxin injections permit to quit habits of tooth grinding and clenching and one single session of injections is curative for 2/3 of the patients. There are no side effects apart from slight diffusion to superficial muscles of the face resulting in a "fixed" smile for about 6 to 8 weeks. So injections of botulinum toxin in masseter and temporalis muscles are an efficient treatment of bruxism and TMJ dysfunction, cheap with no lasting side effect.

Effects of caffeinated chewing gum on muscle pain during submaximal isometric exercise in individuals with fibromyalgia.

Science.gov (United States)

Umeda, Masataka; Kempka, Laura; Weatherby, Amy; Greenlee, Brennan; Mansion, Kimberly

2016-04-01

Physical activity is important to manage symptom of fibromyalgia (FM); however, individuals with FM typically experience augmented muscle pain during exercise. This study examined the effects of caffeinated chewing gum on exercise-induced muscle pain in individuals with FM. This study was conducted with a double-blind, placebo-controlled, cross-over design. Twenty-three patients with FM completed a caffeine condition where they consumed a caffeinated chewing gum that contains 100mg of caffeine, and a placebo condition where they consumed a non-caffeinated chewing gum. They completed isometric handgrip exercise at 25% of their maximal strength for 3 min, and muscle pain rating (MPR) was recorded every 30s during exercise. Clinical pain severity was assessed in each condition using a pain questionnaire. The order of the two conditions was randomly determined. MPR increased during exercise, but caffeinated chewing gum did not attenuate the increase in MPR compared to placebo gum. Clinical pain severity was generally associated with the average MPR and the caffeine effects on MPR, calculated as difference in the average MPR between the two conditions. The results suggest that more symptomatic individuals with FM may experience greater exercise-induced muscle pain, but benefit more from caffeinated chewing gum to reduce exercise-induced muscle pain. Copyright © 2016 Elsevier Inc. All rights reserved.

Reversed Palmaris Longus Muscle Causing Volar Forearm Pain and Ulnar Nerve Paresthesia.

Science.gov (United States)

Bhashyam, Abhiram R; Harper, Carl M; Iorio, Matthew L

2017-04-01

A case of volar forearm pain associated with ulnar nerve paresthesia caused by a reversed palmaris longus muscle is described. The patient, an otherwise healthy 46-year-old male laborer, presented after a previous unsuccessful forearm fasciotomy for complaints of exercise exacerbated pain affecting the volar forearm associated with paresthesia in the ulnar nerve distribution. A second decompressive fasciotomy was performed revealing an anomalous "reversed" palmaris longus, with the muscle belly located distally. Resection of the anomalous muscle was performed with full relief of pain and sensory symptoms. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Human brain activity associated with painful mechanical stimulation to muscle and bone

OpenAIRE

Maeda, Lynn; Ono, Mayu; Koyama, Tetsuo; Oshiro, Yoshitetsu; Sumitani, Masahiko; Mashimo, Takashi; Shibata, Masahiko

2011-01-01

Purpose The purpose of this study was to elucidate the central processing of painful mechanical stimulation to muscle and bone by measuring blood oxygen level-dependent signal changes using functional magnetic resonance imaging (fMRI). Methods Twelve healthy volunteers were enrolled. Mechanical pressure on muscle and bone were applied at the right lower leg by an algometer. Intensities were adjusted to cause weak and strong pain sensation at either target site in preliminary testing. Brain ac...

Changed activation, oxygenation, and pain response of chronically painful muscles to repetitive work after training interventions: a randomized controlled trial

DEFF Research Database (Denmark)

Søgaard, Karen; Blangsted, Anne Katrine; Nielsen, Pernille Kofoed

2012-01-01

The aim of this randomized controlled trial was to assess changes in myalgic trapezius activation, muscle oxygenation, and pain intensity during repetitive and stressful work tasks in response to 10 weeks of training. In total, 39 women with a clinical diagnosis of trapezius myalgia were randomly...... levels of pain. SST lowered the relative EMG amplitude by 36%, and decreased pain during resting and working conditions by 52 and 38%, respectively, without affecting trapezius oxygenation. In conclusion, GFT performed as leg-bicycling decreased pain development during repetitive work tasks, possibly due...... assigned to: (1) general fitness training performed as leg-bicycling (GFT); (2) specific strength training of the neck/shoulder muscles (SST) or (3) reference intervention without physical exercise. Electromyographic activity (EMG), tissue oxygenation (near infrared spectroscopy), and pain intensity were...

Muscle impingement: MR imaging of a painful complication of osteochondromas

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Uri, D.S. [Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104 (United States); Dalinka, M.K. [Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104 (United States); Kneeland, J.B. [Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104 (United States)

1996-10-01

The purpose of this study was to describe the magnetic resonance (MR) appearance of a newly recognized complication of osteochondromas. Two patients presented with pain and swelling over known osteochondromas. Plain radiographic studies were unrevealing. MR examinations were obtained to characterize the exostoses further and evaluate areas of palpable fullness. Increased signal was present in the muscles on T2-weighted images, which correlated with physical findings and was believed to represent muscle injury due to the osteochondroma. Pain and fullness may result from a number of osteochondroma-related complications, the most worrisome of which is malignant degeneration. Muscular impingement and injury should be considered in the differential diagnosis of pain and swelling in the region of an exostosis. MR imaging allows distinction of this entity, which may be radiographically occult and confused clinically with fracture, bursitis, or malignant degeneration. (orig.). With 2 figs.

Muscle impingement: MR imaging of a painful complication of osteochondromas

International Nuclear Information System (INIS)

Uri, D.S.; Dalinka, M.K.; Kneeland, J.B.

1996-01-01

The purpose of this study was to describe the magnetic resonance (MR) appearance of a newly recognized complication of osteochondromas. Two patients presented with pain and swelling over known osteochondromas. Plain radiographic studies were unrevealing. MR examinations were obtained to characterize the exostoses further and evaluate areas of palpable fullness. Increased signal was present in the muscles on T2-weighted images, which correlated with physical findings and was believed to represent muscle injury due to the osteochondroma. Pain and fullness may result from a number of osteochondroma-related complications, the most worrisome of which is malignant degeneration. Muscular impingement and injury should be considered in the differential diagnosis of pain and swelling in the region of an exostosis. MR imaging allows distinction of this entity, which may be radiographically occult and confused clinically with fracture, bursitis, or malignant degeneration. (orig.). With 2 figs

Influence of genotype on contractile protein differentiation in different bovine muscles during foetal life

OpenAIRE

Gagnière , Hélène; Ménissier , François; Geay , Yves; Picard , Brigitte

2000-01-01

International audience; The purpose of this work was to compare muscle fibre differentiation in two genetic types: "normal charolais" and double-muscled (DM) "INRA 95" cattles displaying muscle hypertrophy. Six muscles with different contractile and metabolic characteristics in adult animal: Masseter, Diaphragma (Di), Biceps femoris (BF), Longissimus thoracis, Semitendinosus and Cutaneus trunci (CT) were excised from 60 to 260-day-old fœtuses of both genotypes. These muscles present different...

The smart Peano fluidic muscle: a low profile flexible orthosis actuator that feels pain

Science.gov (United States)

Veale, Allan J.; Anderson, Iain A.; Xie, Shane Q.

2015-03-01

Robotic orthoses have the potential to provide effective rehabilitation while overcoming the availability and cost constraints of therapists. These orthoses must be characterized by the naturally safe, reliable, and controlled motion of a human therapist's muscles. Such characteristics are only possible in the natural kingdom through the pain sensing realized by the interaction of an intelligent nervous system and muscles' embedded sensing organs. McKibben fluidic muscles or pneumatic muscle actuators (PMAs) are a popular orthosis actuator because of their inherent compliance, high force, and muscle-like load-displacement characteristics. However, the circular cross-section of PMA increases their profile. PMA are also notoriously unreliable and difficult to control, lacking the intelligent pain sensing systems of their biological muscle counterparts. Here the Peano fluidic muscle, a new low profile yet high-force soft actuator is introduced. This muscle is smart, featuring bioinspired embedded pressure and soft capacitive strain sensors. Given this pressure and strain feedback, experimental validation shows that a lumped parameter model based on the muscle geometry and material parameters can be used to predict its force for quasistatic motion with an average error of 10 - 15N. Combining this with a force threshold pain sensing algorithm sets a precedent for flexible orthosis actuation that uses embedded sensors to prevent damage to the actuator and its environment.

Effect of cycling on oxygenation of relaxed neck/shoulder muscles in women with and without chronic pain

DEFF Research Database (Denmark)

Andersen, Lars L; Blangsted, Anne Katrine; Nielsen, Pernille Kofoed

2010-01-01

Work-related neck/shoulder muscle pain has been associated with increased anaerobic muscle metabolism. Thus, interventions to enhance oxygenation of painful muscles seem relevant. While cycling with relaxed shoulders has been shown to result in acute neck/shoulder muscle pain reduction, the effect...... on tissue oxygenation remains unknown. The aim of the present study was to investigate tissue oxygenation of the passive trapezius muscle during and after cycling in female workers with (MYA) and without (CON) trapezius myalgia. Eligible participants (n = 17 MYA, n = 8 CON) performed 20 min sub...... increases oxygenation of resting neck/shoulder muscles in women with and without trapezius myalgia, indicating acute positive effects of either neural or humoral factors on vascular beds of distant relaxed muscles. Although this beneficial response was observed in both groups, the post-exercise response...

Neck muscle vibration can improve sensorimotor function in patients with neck pain.

Science.gov (United States)

Beinert, Konstantin; Keller, Martin; Taube, Wolfgang

2015-03-01

People with neck pain display a diminished joint position sense and disturbed postural control, which is thought to be a result of impaired somatosensory afferent activity and/or integration. Afferent processing can be artificially manipulated by vibration and was shown to reduce motor performance in healthy subjects. However, the effect of vibration on sensorimotor function in neck pain patients is scarcely investigated. To assess the effect of neck muscle vibration on joint position sense and postural control in neck pain subjects and healthy controls. Case control study. Thirteen neck pain patients and 10 healthy controls participated in the present study. Cervical joint position sense and dynamic and static postural stability. Short-term, targeted neck muscle vibration with 100 Hz was applied after baseline measurement. Vibration had opposite effects in patients and healthy subjects. Patients showed improved joint position sense (pneck pain. Thus, vibration may be used to counteract sensorimotor impairment of the cervical spine. Potential underlying mechanisms are discussed. Copyright © 2015. Published by Elsevier Inc.

Influence of Botulinumtoxin A on the Expression of Adult MyHC Isoforms in the Masticatory Muscles in Dystrophin-Deficient Mice (Mdx-Mice

Directory of Open Access Journals (Sweden)

Ute Ulrike Botzenhart

2016-01-01

Full Text Available The most widespread animal model to investigate Duchenne muscular dystrophy is the mdx-mouse. In contrast to humans, phases of muscle degeneration are replaced by regeneration processes; hence there is only a restricted time slot for research. The aim of the study was to investigate if an intramuscular injection of BTX-A is able to break down muscle regeneration and has direct implications on the gene expression of myosin heavy chains in the corresponding treated and untreated muscles. Therefore, paralysis of the right masseter muscle was induced in adult healthy and dystrophic mice by a specific intramuscular injection of BTX-A. After 21 days the mRNA expression and protein content of MyHC isoforms of the right and left masseter, temporal, and the tongue muscle were determined using quantitative RT-PCR and Western blot technique. MyHC-IIa and MyHC-I-mRNA expression significantly increased in the paralyzed masseter muscle of control-mice, whereas MyHC-IIb and MyHC-IIx/d-mRNA were decreased. In dystrophic muscles no effect of BTX-A could be detected at the level of MyHC. This study suggests that BTX-A injection is a suitable method to simulate DMD-pathogenesis in healthy mice but further investigations are necessary to fully analyse the BTX-A effect and to generate sustained muscular atrophy in mdx-mice.

Comparison of Muscle Fatigue Effects on Electromyographic Onset Latency of Trapezius Muscle in Posterior-Anterior Perturbation between Patients with Chronic Neck Pain and Healthy Persons

Directory of Open Access Journals (Sweden)

Zahra Rojhani-Shirazi

2008-07-01

Full Text Available Objective: Fatigue process in patients with neck pain was happened more quickly than healthy persons and neck muscle fatigue increased body sway during standing, but there is less evidence about the behavior of these muscles in dynamic conditions such as external perturbation, so this study was done to investigate the effect of muscle fatigue on onset latency of upper trapezius muscle in posterior-anterior perturbation among patients with chronic neck pain and healthy individuals. Materials & Methods: In this quasi experimental and interventional study 16 patients with chronic neck pain (intervention group and 16 healthy individuals (control group were selected by simple and convenient sampling and based on inclusive and exclusive criteria. Data collection was done by using questionnaire and doing some tests and the main equipments were dynamometer, accelerometer and surface electromyography. The weight equal to 30% of maximum voluntary contraction used to produce fatigue process and 10% of body weight used to produce perturbation. Independent T test, Paired T test and Repeated ANOVA were used for data analysis. Results: There was significant difference in onset latency of upper Trapezius muscle in posterior – anterior perturbation between two groups, before (P=0.006 and after (P=0.026 fatigue. This means that the onset latency was increased in healthy individuals and decreased in patients after fatigue. Also, there was significant difference in onset latency of Trapezius muscle in posterior – anterior perturbation between before and after fatigue in patients group (P<0.001 and healthy persons group (P=0.04. Conclusion: Pain can change the onset latency of trapezius muscle and possibly it can decrease muscle activity in deep muscle and change the pattern of muscle activation. Fatigue as an exaggerated risk factor can decrease onset latency of superficial muscle in patients with chronic neck pain to stabilize the system, that it can increase

Cervico-mandibular muscle activity in females with chronic cervical pain

OpenAIRE

T. Lang; R. Parker; T. Burgess

2013-01-01

Pathophysiological mechanisms behind pain in chroniccervical musculoskeletal conditions (MSC) in office workers remainunclear. Chronic cervical pain has established links with temporomandibular(TM) disorders. Yet there is no current published evidence to reportwhether individuals with cervical dysfunction exhibit altered masseterand cervical extensor (CE) muscle activity. Objective: To explore CE andmasseter surface electromyographic (sEMG) activity and teeth clenchinghabits in females with c...

Effect of contrasting physical exercise interventions on rapid force capacity of chronically painful muscles

DEFF Research Database (Denmark)

Andersen, Lars L; Andersen, Jesper L; Suetta, Charlotte

2009-01-01

as neural and muscular adaptations in women with chronic neck muscle pain. A group of employed women (n = 42) with a clinical diagnosis of trapezius myalgia participated in a 10-wk randomized controlled trial; specific strength training of the neck/shoulder muscles, general fitness training performed as leg...... to rehabilitation with specific strength training. The underlying mechanisms were related to both pain reduction and general neuromuscular adaptations to strength training. Potentially, the present method can be a useful clinical screening tool of muscle function in rehabilitation settings....

Torque-EMG-velocity relationship in female workers with chronic neck muscle pain

DEFF Research Database (Denmark)

Andersen, Lars L; Nielsen, Pernille K; Søgaard, Karen

2008-01-01

The present study investigated the effect of chronic neck muscle pain (defined as trapezius myalgia) on neck/shoulder muscle function during concentric, eccentric and static contraction. Forty-two female office workers with trapezius myalgia (MYA) and 20 healthy matched controls (CON) participated...

The relationships between measures of stature recovery, muscle activity and psychological factors in patients with chronic low back pain.

Science.gov (United States)

Lewis, Sandra; Holmes, Paul; Woby, Steve; Hindle, Jackie; Fowler, Neil

2012-02-01

Individuals with low back pain (LBP) often exhibit elevated paraspinal muscle activity compared to asymptomatic controls during static postures such as standing. This hyperactivity has been associated with a delayed rate of stature recovery in individuals with mild LBP. This study aimed to explore this association further in a more clinically relevant population of NHS patients with LBP and to investigate if relationships exist with a number of psychological factors. Forty seven patients were recruited from waiting lists for physiotherapist-led rehabilitation programmes. Paraspinal muscle activity while standing was assessed via surface electromyogram (EMG) and stature recovery over a 40-min unloading period was measured on a precision stadiometer. Self-report of pain, disability, anxiety, depression, pain-related anxiety, fear of movement, self-efficacy and catastrophising were recorded. Correlations were found between muscle activity and both pain (r=0.48) and disability (r=0.43). Muscle activity was also correlated with self-efficacy (r=-0.45), depression (r=0.33), anxiety (r=0.31), pain-related anxiety (r=0.29) and catastrophising (r=0.29) and was a mediator between self-efficacy and pain. Pain was a mediator in the relationship between muscle activity and disability. Stature recovery was not found to be related to pain, disability, muscle activity or any of the psychological factors. The findings confirm the importance of muscle activity within LBP, in particular as a pathway by which psychological factors may impact on clinical outcome. The mediating role of muscle activity between psychological factors and pain suggests that interventions that are able to reduce muscle tension may be of particular benefit to patients demonstrating such characteristics, which may help in the targeting of treatment for LBP. Copyright © 2011 Elsevier Ltd. All rights reserved.

Changes in the main masticatory muscles in CT after mandibular condyle fracture

International Nuclear Information System (INIS)

Raustia, A.M.; Oikarinen, K.S.; Pyhtinen, J.

1990-01-01

The aim was to study changes in the main masticatory muscles after mandibular condyle fracture as seen by CT, comparing the densities and sizes of the masseter, medial pterygoid and lateral pterygoid muscles on the fractured side with those on the non-fractured side. More or less permanent muscular changes are detectable several years after the accident, especially in the lateral pterygoid muscle, which is attached to the condylar head. This muscle was statistically significantly smaller (p [de

The use of a custom-made mouthguard stabilizes the electromyographic activity of the masticatory muscles among Karate-Dō athletes.

Science.gov (United States)

Raquel, Gilsane; Namba, Eli Luis; Bonotto, Daniel; Ribeiro Rosa, Edvaldo Antônio; Trevilatto, Paula Cristina; Naval Machado, Maria Ângela; Vianna-Lara, Michelle Santos; Azevedo-Alanis, Luciana Reis

2017-01-01

To analyze and compare the electromyographic activity of the temporal (anterior portion) and masseter muscles among Karate-Dō athletes before and after training, with and without the use of a mouthguard. Twenty athletes (14 males and 6 females) with a mean age of 23.7 ± 7.5 years participated. They had surface electromyography recordings taken of their bilateral temporal and masseter muscles before and after training under the following conditions: no mouthguard, with a ready-made mouthguard, and with a custom-made mouthguard. Activity was examined at mandibular rest, while clenching, and at maximum voluntary contraction. The data were normalized using the mean maximum voluntary contraction. The right (p = 0.005) and left (p = 0.015) temporal muscles showed significantly lower electromyographic activity with a custom-made mouthguard compared with no mouthguard after training while clenching. The electromyographic activity of the temporal and masseter muscles did not show significant differences when tested at mandibular rest and while clenching before or after training with a custom-made mouthguard (p > 0.05). The use of a custom-made mouthguard preserved participants' electromyographic profiles before and after training; thus, they allow for stable muscle activity during the training of Karate-Dō athletes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Myofascial involvement of supra- and infraspinatus muscles contributes to ipsilateral shoulder pain after muscle-sparing thoracotomy and video-assisted thoracic surgery.

Science.gov (United States)

Ohmori, Aki; Iranami, Hiroshi; Fujii, Keisuke; Yamazaki, Akinori; Doko, Yukari

2013-12-01

This study examined the hypothesis that ipsilateral upper extremity elevation for muscle-sparing thoracotomy procedures contributes to the postoperative shoulder pain. Prospective observational study. Medical center. ASA physical status 1-2 patients undergoing elective lung surgeries including pneumonectomy, lobectomy, and segmentectomy performed through either the anterolateral approach or video-assisted thoracotomy surgery. Postoperative observation of ipsilateral shoulder pain. Postoperative examinations of sites of shoulder pain (clavicle, anterior, lateral,or posterior aspect of acromion, posterior neck, supraspinatus, infraspinatus, and these entire areas) with or without trigger points, visual analog scale score of wound pain, and requested counts of analgesics. The number of patients who suffered from postoperative shoulder pain was 37 of 70 (52.9%). Demographic data, anterolateral/VATS ratio, VAS scores, and requested counts of rescue analgesics requirement were similar in the groups of patients with and without postoperative shoulder pain. The segmentectomy caused a significantly higher incidence of postoperative shoulder pain compared with other procedures (p shoulder pain showed defined trigger points in their painful areas. These results supported the hypothesis that myofascial involvement contributed, to some extent, to shoulder pain after muscle-sparing thoracotomy with ipsilateral upper extremity elevation. Copyright © 2013 Elsevier Inc. All rights reserved.

Dor muscular em cabeça e pescoço e medidas vocais acústicas de fonte glótica Head and neck muscles pain and glottic source acoustical vocal measures

Directory of Open Access Journals (Sweden)

Luane de Moraes Boton

2012-02-01

Full Text Available OBJETIVO: verificar a relação entre a presença de dor na musculatura da cabeça, face, boca e pescoço envolvidos no processo fisiológico da função mastigatória e nos aspectos lateral e posterior da articulação temporomandibular (ATM e medidas vocais acústicas da fonte glótica. MÉTODO: amostra de 24 mulheres com idades entre 16 e 56 anos com queixas e sintomatologia de Disfunção Temporomandibular (DTM. Aplicação de um questionário de anamnese, exame clínico específico para verificação da presença de dor na musculatura da cabeça, face, boca e pescoço e nas ATM; avaliações otorrinolaringológica, do sistema estomatognático, audiológica e gravação digital da voz com análise vocal acústica da fonte glótica por meio do software Multi Dimensional Voice Program Advanced da KayPENTAX. Os resultados obtidos foram analisados estatisticamente pelo teste do qui-quadrado ao nível de significância de 0,05. RESULTADOS: houve significância estatística entre: ausência de dor no masseter superficial e alteração do índice de turbulência vocal (VTI; ausência de dor no aspecto posterior da ATM e alteração do coeficiente de perturbação do pitch (PPQ e alteração da variação da frequência fundamental (vf0; presença de dor no pterigóideo medial e normalidade do grau de quebra vocal (DVB. CONCLUSÃO: verificou-se que não houve relação entre as medidas de voz alteradas e a presença de dor nos músculos avaliados, mas algumas medidas alteradas se relacionaram com a ausência de dor muscular, sugerindo que outros aspectos da DTM, que não a dor, podem ocasionar alteração de medidas vocais acústicas.PURPOSE: to check the relationship between pain presence in head, face, mouth and neck muscles involved in the physiological process of chewing function and in the lateral and posterior aspects of temporomandibular joint (ATM and acoustical glottic source vocal measures. METHOD: 24 women with ages varying between 16 and

Mouse preferential incising force orientation changes during jaw closing muscle hyperalgesia and is sex dependent.

Science.gov (United States)

Widmer, C G; Morris-Wiman, J

2016-12-01

Mouse incising is controlled by a central pattern generator and this activity can change in the presence of pain. The incising frequency and maximum force generation decreases with pain. In this study, we used repetitive acidic injections in the left masseter muscle of male and female mice to determine differences between baseline and jaw muscle pain conditions and the effect of sex on preferential incising direction. A within subject design was used to evaluate data previously acquired using multi-axis force data (X, Y and Z) from the 4th baseline recording day and day 7 post-injection (day of maximal pain response) for each mouse of each sex. A total of 34 female and male (age 3-9months) CD-1 mice were evaluated. After mathematically rotating the X and Y axes to align the Y axis to be parallel to the wire struts of the cage top, data were analyzed to determine incising direction preference during baseline (non-pain) and pain (day 7) conditions and between sex. Radar plots of X-Y, X-Z and Y-Z axes depicted the average direction of incising preference between baseline and pain conditions for each sex. Statistical differences among groups were tested using a mixed model ANOVA. Similar to previous findings, female mice had a more robust difference in incising direction preference when comparing male and female pain conditions and this was most evident in the X-Z axes. The incising frequencies most commonly affected were 5.3, 6.2 and 7.6Hz. Male mice varied little in their incising direction preference between the baseline and pain conditions. In addition, statistical comparison of ratios of the percent of time spent incising in the Z versus X axes for each incising frequency found that the incising preference was not different when comparing 5.3 and 7.6Hz frequencies. Finally, female mice used a novel approach to minimize pain while incising by rotating their head and body nearly 180 degrees while males did not use this strategy as frequently. The preferred incising

Effects of proprioceptive circuit exercise on knee joint pain and muscle function in patients with knee osteoarthritis.

Science.gov (United States)

Ju, Sung-Bum; Park, Gi Duck; Kim, Sang-Soo

2015-08-01

[Purpose] This study applied proprioceptive circuit exercise to patients with degenerative knee osteoarthritis and examined its effects on knee joint muscle function and the level of pain. [Subjects] In this study, 14 patients with knee osteoarthritis in two groups, a proprioceptive circuit exercise group (n = 7) and control group (n = 7), were examined. [Methods] IsoMed 2000 (D&R Ferstl GmbH, Hemau, Germany) was used to assess knee joint muscle function, and a Visual Analog Scale was used to measure pain level. [Results] In the proprioceptive circuit exercise group, knee joint muscle function and pain levels improved significantly, whereas in the control group, no significant improvement was observed. [Conclusion] A proprioceptive circuit exercise may be an effective way to strengthen knee joint muscle function and reduce pain in patients with knee osteoarthritis.

Patients with Concomitant Chronic Neck Pain and Myofascial Pain in Masticatory Muscles Have More Widespread Pain and Distal Hyperalgesia than Patients with Only Chronic Neck Pain.

Science.gov (United States)

Muñoz-García, Daniel; López-de-Uralde-Villanueva, Ibai; Beltrán-Alacreu, Héctor; La Touche, Roy; Fernández-Carnero, Josué

2017-03-01

Insufficient evidence exists to compare widespread pain (WP), pain sensibility, and psychological factors that occur in patients presenting with chronic neck pain (CNP) or a combination of temporomandibular disorder (TMD) and other complaints. The present study compared the pain sensibility and psychological factors of subjects with CNP with those with TMD + CNP. Cross-sectional study. Local community. A nonprobabilistic convenience sample of 86 persons with CNP or TMD was recruited into three groups: CNP, TMD with myofascial pain in masticatory muscles with cocomitant CNP (TMD + CNP), and asymptomatic control groups consisted of 27, 29, and 30 participants, respectively. Participants underwent a clinical examination to evaluate WP with computerized assessment based on the pain drawing, pressure pain thresholds (PPT), and psychological factors, which were evaluated using the pain catastrophizing scale (PCS) and the state-trait anxiety inventory (STAI). Statistically significant differences were observed between participants with CNP and TMD + CNP for WP (t = -2.80, P  < 0.01, d = -1.06). Post hoc analyses only revealed significant differences between TMD + CNP participants and asymptomatic controls for PPT at extratrigeminal areas. Pearson correlation analyses showed a moderate positive association between symptomatic groups within the WP and STAI ( P  < 0.05) and a moderate negative association between PCS and PPT ( P  < 0.05) at the right tibialis muscle. TMD + CNP participants had more areas of pain and also showed widespread pain hyperalgesia. Both groups of participants had psychological factors positively associated with STAI and WP; further, PCS and the PPT at the extratrigeminal region were negatively associated with each other in both groups, except for the left tibialis in the TMD + CNP group. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Masticatory muscle and temporomandibular joint pain in Croatian war veterans with posttraumatic stress disorder.

Science.gov (United States)

Uhac, Ivone; Tariba, Petra; Kovac, Zoran; Simonić-Kocijan, Suncana; Lajnert, Vlatka; Mesić, Vesna Fugosić; Kuis, Davor; Braut, Vedrana

2011-12-01

The aim of this study was to investigate the prevalence and intensity of masticatory muscle and temporomandibular joint (TMJ) pain in Croatian war veterans with posttraumatic stress disorder (PTSD). The examined group consisted of 100 Croatian war veterans, in whom PTSD had previously been diagnosed. Patients were compared with 92 subjects who had not taken part in the war and in whom PTSD was excluded by psychiatric examination. The clinical examination consisted of palpation of the masticatory muscles, the prominent neck musculature, and TMJ. The examination technique used and the definition of items were previously tested for reliability and validity. 93% of the subjects with PTSD had masticatory muscle tenderness compared to 45.65% of the subjects in the control group (chi2 = 51.46, p < 0.0001). The most frequent painful location in the subjects with PTSD was the left lateral pterygoid site in 88%, and in subjects of the control group the right lateral pterygoid site in 28.26% of cases. The most painful location in the PTSD group was the left lateral pterygoid site in 72%, and in the control group the left posterior digastric in 4.35% of cases. 58% of the subjects with PTSD had TMJ tenderness compared to 3.26% of subjects in the control group (chi2 = 66.23, p < 0.0001). The most frequent painful location of TMJ in both groups was the left posterior capsule; in the PTSD group 38% and in subjects in the control group 2.17% of cases. The most painful location was the left posterior capsule in 28% of subjects with PTSD, while not one subject in the control group reported severe painful sensitivity. The very high frequency and intensity of pain in subjects with PTSD confirms the effect of stress on muscle and joint sensitivity, i.e. perception of pain.

The effect of oxfendazole treatment on muscle pathology in pigs infected with Taenia solium cysticercosis

DEFF Research Database (Denmark)

Iburg, Tine Moesgaard; Karlsson, Madeleine; Spång, Frederic

2012-01-01

The aim of the present study was to test histopathologically the hypothesis that the time for clearing Taenia solium cysts in muscle tissue of pigs following treatment with oxfendazole is cyst density dependant. A total of 248 cyst lesions in the masseter muscle of 28 naturally infected pigs were...

Effect of physical training on function of chronically painful muscles: A randomized controlled trial

DEFF Research Database (Denmark)

Andersen, Lars L; Andersen, Christoffer H; Zebis, Mette K

2008-01-01

.01-0.05). While EMG activity of the unaffected deltoid remained unchanged during the maximal contractions, an increase in EMG amplitude (42-86%, Ppower frequency (19%, Ppainful trapezius muscle. Correspondingly, torque increased 18-53% (P...Purpose: Pain and tenderness of the upper trapezius muscle is frequent in several occupational groups. The objective of this study is to investigate the effect of three contrasting interventions on muscle function and pain in women with trapezius myalgia. Methods: A group of employed women (n=42...... and electromyography (EMG) were recorded during maximal shoulder abductions in an isokinetic dynamometer at -60, 60, 0 and 180 degrees (.)s(-1). Further, a submaximal reference contraction with only the load of the arms was performed. Results: Significant changes were observed only in SST. Pain decreased 42-49% (P

Optimal duration of ultra low frequency-transcutaneous electrical nerve stimulation (ULF-TENS) therapy for muscular relaxation in neuromuscular occlusion: A preliminary clinical study.

Science.gov (United States)

Esclassan, Rémi; Rumerio, Anaïs; Monsarrat, Paul; Combadazou, Jean Claude; Champion, Jean; Destruhaut, Florent; Ghrenassia, Christophe

2017-05-01

The primary aim of this work was to determine the duration of ultra-low-frequency transcutaneous electrical nerve stimulation (ULF-TENS) application necessary to achieve sufficient relaxation of the masticatory muscles. A secondary aim was to analyze the influence of stimulation on muscle relaxation in pathological subjects and determine whether ULF-TENS has a noteworthy impact on muscle relaxation. Sixteen adult subjects with temporomandibular disorders (TMD) and muscle pain and a group of four control subjects were included in this study. ULF-TENS was applied, and muscular activities of the masseter, temporal, and sternocleidomastoid muscles (SCM) were recorded for 60 min. Significant relaxation was achieved in the TMD group from 20, 40, and 60 min for the temporal, masseter, and SCM muscles (p TENS application would last 40 min to obtain sufficient muscle relaxation both in patients with masticatory system disorders and healthy subjects, a time constraint that is consistent with everyday clinical practice.

Can short-term oral fine motor training affect precision of task performance and induce cortical plasticity of the jaw muscles?

DEFF Research Database (Denmark)

Hong, Zhang; Kumar, Abhishek; Kothari, Mohit

2016-01-01

The aim was to test the hypothesis that short-term oral sensorimotor training of the jaw muscles would increase the precision of task performance and induce neuroplastic changes in the corticomotor pathways, related to the masseter muscle. Fifteen healthy volunteers performed six series with ten...... trials of an oral sensorimotor task. The task was to manipulate and position a spherical chocolate candy in between the anterior teeth and split it into two equal halves. The precision of the task performance was evaluated by comparing the ratio between the two split halves. A series of "hold......-and-split" tasks was also performed before and after the training. The hold force and split force along with the electromyographic (EMG) activity of jaw muscles were recorded. Motor-evoked potentials and cortical motor maps of the right masseter muscle were evoked by transcranial magnetic stimulation...

The relationship between abdominal muscle activity and pain, disability and fear of movement during standing postural tasks in females with chronic nonspecific low back pain

Directory of Open Access Journals (Sweden)

Fatemeh Ehsani

2016-10-01

Full Text Available Introduction: It appears that the level of fear of movement changes deep trunk muscle activity in the patients with low back pain (LBP. There is no study to investigate the relationship between deep trunk muscle activity and fear of movement in the patients with LBP. Thus, the purpose of this study was to assess the relationship between abdominal muscle activity and pain, disability and fear of movement during standing postural tasks in females with chronic nonspecific LBP. Materials and Methods: Forty four females participated were asked to maintain their balance during standing on the platform stability levels of Biodex Balance System (BBS. Concurrently, ultrasonography (US data about abdominal muscles thickness measurement were transferred and saved to process offline. The pain intensity, disability and fear of movement were assessed by valid scales and questionnaire. Results: There was not significant correlation between abdominal muscle thickness changes and pain and disability intensity (P>0.05, while significant and inverse correlation between deep abdominal muscle thickness changes and fear of movement was observed in the patients (P<0.05, although this correlation is weak (r= -0.36- -0.32. Conclusion: It seems that increases in fear of movement decrease significantly deep abdominal muscles activity in the patients with LBP. This relationship demonstrates the importance of cognitive behavioral therapy and controlling fear of movement on improvement of deep abdominal muscle activity in the patients with LBP

Progressive shoulder-neck exercise on cervical muscle functions in middle-aged and senior patients with chronic neck pain.

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Lin, I-Hsien; Chang, Kwang-Hwa; Liou, Tsan-Hon; Tsou, Chih-Min; Huang, Yi-Ching

2018-02-01

Although neck pain is a common musculoskeletal disorder, there is no consensus on suitable exercise methods for middle-aged and senior patients with chronic neck pain. Therefore, this study investigated the effectiveness of a 6-week shoulder-neck exercise intervention program on cervical muscle function improvement in patients aged 45 years or older with chronic neck pain. The aim of the present study was to evaluate the effects of progressive shoulder-neck exercise on cervical muscle functions of middle-aged and senior patients with chronic neck pain. A randomized controlled single-blind trial. Rehabilitation department of a hospital. A total of 72 subjects aged ≥45 years with chronic neck pain were randomly allocated to either an experimental group (N.=36; age 57.3±8.74 years) or a control group (N.=36; age 58.15±8.17 years). The control group received only traditional physiotherapy, whereas the experimental group participated in a 6-week shoulder-neck exercise program consisting of cranio-cervical flexion and progressive resistance exercises in addition to receiving traditional physiotherapy. The muscle functions of subjects in both groups were tested before the experiment and also after the intervention program. The pretest and posttest measured the cranio-cervical flexion test (CCFT) and the superficial cervical muscle strength. After the intervention, the experimental group had a 56.48 point improvement in the performance index of the CCFT (Pcervical muscle functions. This study confirmed that the 6-week progressive shoulder-neck exercise program can effectively improve cervical muscle function in middle-aged and senior patients with chronic neck pain. Progressive shoulder-neck exercise might provide positive effect on deep and superficial neck muscle strength in patients with chronic neck pain. Therefore, this study may serve as a reference for the clinical rehabilitation of patients with chronic neck pain.

Local myogenic pulp-derived cell injection enhances craniofacial muscle regeneration in vivo.

Science.gov (United States)

Jung, J E; Song, M J; Shin, S; Choi, Y J; Kim, K H; Chung, C J

2017-02-01

To enhance myogenic differentiation in pulp cells isolated from extracted premolars by epigenetic modification using a DNA demethylation agent, 5-aza-2'-deoxycytidine (5-Aza), and to evaluate the potent stimulatory effect of 5-Aza-treated pulp cell injection for craniofacial muscle regeneration in vivo. Pulp cells were isolated from premolars extracted for orthodontic purposes from four adults (age range, 18-22.1 years). Levels of myogenic differentiation and functional contraction response in vitro were compared between pulp cells with or without pre-treatment of 5-Aza. Changes in muscle regeneration in response to green fluorescent protein (GFP)-labelled myogenic pulp cell injection in vivo were evaluated using a cardiotoxin (CTX)-induced muscle injury model of the gastrocnemius as well as the masseter muscle in mice. Pre-treatment of 5-Aza in pulp cells stimulated myotube formation, myogenic differentiation in terms of desmin and myogenin expression, and the level of collagen gel contraction. The local injection of 5-Aza pre-treated myogenic pulp cells was engrafted into the host tissue and indicated signs of enhanced muscle regeneration in both the gastrocnemius and the masseter muscles. The epigenetic modification of pulp cells from extracted premolars and the local injection of myogenic pulp cells may stimulate craniofacial muscles regeneration in vivo. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Longitudinal evaluation of jaw muscle activity and mandibular kinematics in young patients with Class II malocclusion treated with the Teuscher activator.

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Cuevas, Maria-José; Cacho, Alberto; Alarcón, Jose-Antonio; Martín, Conchita

2013-05-01

A longitudinal study was performed to evaluate the jaw muscle activity and mandibular kinematics after Teuscher activator treatment and at 2 years after orthodontic treatment completion. Twenty-seven children with Class II division 1 malocclusion were evaluated before treatment (T0; mean: 11.6 years), after functional treatment (T1; mean: 12.8 years), and 2 years after orthodontic treatment (T2; mean: 18 years). Bilateral surface electromyographic activities of the anterior temporalis, posterior temporalis, masseter, and suprahyoid muscle areas were analyzed at rest and during clenching, swallowing, and mastication. Kinematic recordings of the mandibular maximum opening, lateral shift, right and left lateral excursions, and protrusion were evaluated. Compared to T0, the left masseter activity during clenching was decreased at T1 but increased at T2, similar to the other evaluated muscles. The suprahyoid activity during swallowing was increased at T1 but decreased at T2. The masseter activity during mastication was increased at T1 and further increased at T2. The left and right lateral excursions and protrusion did not show significant changes throughout the experiment. Teuscher activator and subsequent fixed orthodontic treatment improved jaw muscle function; however, a long period was needed to attain complete neuromuscular adaptation.

Muscle relaxation for individuals having tattoos removed through laser treatment: possible effects regarding anxiety and pain.

Science.gov (United States)

Huang, Faye; Chou, Wen-Jiun; Chen, Tien-Hsing; Chen, Ching; Hsieh, Yu-Lian; Chong, Mian-Yoon; Hung, Chi-Fa; Lin, Shu-Ching; Tsai, Hsiu-Huang; Wang, Liang-Jen

2016-08-01

Effectively managing pain is vital for the well-being and satisfaction of patients undergoing dermatologic treatments involving lasers. This study investigates the potential outcome of using muscle relaxation techniques to reduce pain among people having their tattoos removed with laser treatment. This study consists of 56 participants (mean age 18.1 ± 2.1 years) that had tattoos removed using the principle of selective photothermolysis. These participants underwent muscle relaxation before receiving the laser treatment. Their peripheral skin temperatures (PST) were measured both at the beginning and the end of the muscle relaxation period. Then, the Beck Anxiety Inventory was applied to evaluate anxiety levels. Once the laser treatment was completed, pain levels were measured using a visual analogue scale. A total of 125 person-sessions of laser treatment and psychometric assessments were performed in this study. The muscle relaxation method significantly increased the PST of the participants while reducing the levels of anxiety and pain throughout the course of the laser treatment procedure. The PST, anxiety scores, and pain scores all showed significant correlations with one another. According to the results obtained, this study proposes that muscle relaxation techniques be considered possibly auxiliary treatment options for individuals having tattoos removed through laser treatment. Additional studies with a comparison group and a larger sample size are required in the future to confirm the effectiveness of such intervention.

Effects of an intervention based on the Transtheoretical Model on back muscle endurance, physical function and pain in rice farmers with chronic low back pain.

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Thanawat, Thanakorn; Nualnetr, Nomjit

2017-01-01

Chronic low back pain (LBP) can be managed by exercises which should be tailored to an individual's readiness to behavioral change. To evaluate the effects of an intervention program based on the Transtheoretical Model of behavioral change (TTM) on back muscle endurance, physical function and pain in rice farmers with chronic LBP. In a 32-week study, 126 rice farmers were allocated to the TTM (n= 62) and non-TTM (n= 64) groups. Modified Biering-Sorensen test, Oswestry Disability Questionnaire and visual analogue scale were used for evaluating back muscle endurance, physical function and severity of pain, respectively. The evaluations were performed at baseline and at weeks 8, 20 and 32 of the study. Data were analyzed using repeated measure ANOVA. The back muscle endurance was significantly greater in the TTM group than in the non-TTM group at week 32 (p= 0.025). Physical function and severity of pain were significantly improved in the TTM group when compared with the non-TTM group at weeks 20 and 32 (pback muscle endurance and physical function, and reduce the pain in rice farmers with LBP. Further studies should be considered to explore the long-term effects of this intervention.

Does Deep Cervical Flexor Muscle Training Affect Pain Pressure Thresholds of Myofascial Trigger Points in Patients with Chronic Neck Pain? A Prospective Randomized Controlled Trial

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Pavlos Bobos

2016-01-01

Full Text Available Background. We need to understand more about how DNF performs in different contexts and whether it affects the pain threshold over myofascial trigger points (MTrPs. Purpose. The objectives were to investigate the effect of neck muscles training on disability and pain and on pain threshold over MTrPs in people with chronic neck pain. Methods. Patients with chronic neck pain were eligible for participation with a Neck Disability Index (NDI score of over 5/50 and having at least one MTrP on either levator scapulae, upper trapezoid, or splenius capitis muscle. Patients were randomly assigned into either DNF training, superficial neck muscle exercise, or advice group. Generalized linear model (GLM was used to detect differences in treatment groups over time. Results. Out of 67 participants, 60 (47 females, mean age: 39.45 ± 12.67 completed the study. Neck disability and neck pain were improved over time between and within groups (p<0.05. However, no differences were found within and between the therapeutic groups (p<0.05 in the tested muscles’ PPTs and in cervicothoracic angle over a 7-week period. Conclusion. All three groups improved over time. This infers that the pain pathways involved in the neck pain relief are not those involved in pain threshold.

Lumbar muscle structure and function in chronic versus recurrent low back pain: a cross-sectional study.

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Goubert, Dorien; De Pauw, Robby; Meeus, Mira; Willems, Tine; Cagnie, Barbara; Schouppe, Stijn; Van Oosterwijck, Jessica; Dhondt, Evy; Danneels, Lieven

2017-09-01

Heterogeneity exists within the low back pain (LBP) population. Some patients recover after every pain episode, whereas others suffer daily from LBP complaints. Until now, studies rarely make a distinction between recurrent low back pain (RLBP) and chronic low back pain (CLBP), although both are characterized by a different clinical picture. Clinical experiences also indicate that heterogeneity exists within the CLBP population. Muscle degeneration, like atrophy, fat infiltration, alterations in muscle fiber type, and altered muscle activity, compromises proper biomechanics and motion of the spinal units in LBP patients. The amount of alterations in muscle structure and muscle function of the paraspinal muscles might be related to the recurrence or chronicity of LBP. The aim of this experimental study is to evaluate differences in muscle structure (cross-sectional area and lean muscle fat index) and muscle activity of the multifidus (MF) and erector spinae (ES) during trunk extension, in patients with RLBP, non-continuous CLBP, and continuous CLBP. This cross-sectional study took place in the university hospital of Ghent, Belgium. Muscle structure characteristics and muscle activity were assessed by magnetic resonance imaging (MRI). Fifty-five adults with non-specific LBP (24 RLBP in remission, 15 non-continuous CLBP, 16 continuous CLBP) participated in this study. Total cross-sectional area, muscle cross-sectional area, fat cross-sectional area, lean muscle fat index, T2-rest and T2-shift were assessed. A T1-weighted Dixon MRI scan was used to evaluate spinal muscle cross-sectional area and fat infiltration in the lumbar MF and ES. Muscle functional MRI was used to evaluate the muscle activity of the lumbar MF and ES during a lumbar extension exercise. Before and after the exercise, a pain assessment was performed. This study was supported by grants from the Special Research Fund of Ghent University (DEF12/AOP/022) without potential conflict of interest

Acupuncture Therapy on Temporomandibular Joint Syndrome

Institute of Scientific and Technical Information of China (English)

XIA Nai-nian; HUANG Ming-juan

2005-01-01

@@ Temporomandibular Joint (TMJ) syndrome, an commonly and frequently encountered disease, is characterized by motor dysfunction of mandibular joint and snapping articular surface as major complaints, and then tinnitus, facial pain and occasional headache, most patients got limited mouth open and pain inside the joints or masseter muscle. The authors of this article have treated 68cases of TMJ syndrome since 2001.

Shape determinative slice localization for patient-specific masseter modeling using shape-based interpolation

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Ng, H.P. [NUS Graduate School for Integrative Sciences and Engineering (Singapore); Biomedical Imaging Lab., Agency for Science Technology and Research (Singapore); Foong, K.W.C. [NUS Graduate School for Integrative Sciences and Engineering (Singapore); Dept. of Preventive Dentistry, National Univ. of Singapore (Singapore); Ong, S.H. [Dept. of Electrical and Computer Engineering, National Univ. of Singapore (Singapore); Div. of Bioengineering, National Univ. of Singapore (Singapore); Liu, J.; Nowinski, W.L. [Biomedical Imaging Lab., Agency for Science Technology and Research (Singapore); Goh, P.S. [Dept. of Diagnostic Radiology, National Univ. of Singapore (Singapore)

2007-06-15

The masseter plays a critical role in the mastication system. A hybrid method to shape-based interpolation is used to build the masseter model from magnetic resonance (MR) data sets. The main contribution here is the localizing of determinative slices in the data sets where clinicians are required to perform manual segmentations in order for an accurate model to be built. Shape-based criteria were used to locate the candidates for determinative slices and fuzzy-c-means (FCM) clustering technique was used to establish the determinative slices. Five masseter models were built in our work and the average overlap indices ({kappa}) achieved is 85.2%. This indicates that there is good agreement between the models and the manual contour tracings. In addition, the time taken, as compared to manually segmenting all the slices, is significantly lesser. (orig.)

Shape determinative slice localization for patient-specific masseter modeling using shape-based interpolation

International Nuclear Information System (INIS)

Ng, H.P.; Foong, K.W.C.; Ong, S.H.; Liu, J.; Nowinski, W.L.; Goh, P.S.

2007-01-01

The masseter plays a critical role in the mastication system. A hybrid method to shape-based interpolation is used to build the masseter model from magnetic resonance (MR) data sets. The main contribution here is the localizing of determinative slices in the data sets where clinicians are required to perform manual segmentations in order for an accurate model to be built. Shape-based criteria were used to locate the candidates for determinative slices and fuzzy-c-means (FCM) clustering technique was used to establish the determinative slices. Five masseter models were built in our work and the average overlap indices (κ) achieved is 85.2%. This indicates that there is good agreement between the models and the manual contour tracings. In addition, the time taken, as compared to manually segmenting all the slices, is significantly lesser. (orig.)

Comparison of muscle and joint pressure-pain thresholds in patients with complex regional pain syndrome and upper limb pain of other origin.

Science.gov (United States)

Mainka, Tina; Bischoff, Florian S; Baron, Ralf; Krumova, Elena K; Nicolas, Volkmar; Pennekamp, Werner; Treede, Rolf-Detlef; Vollert, Jan; Westermann, Andrea; Maier, Christoph

2014-03-01

Pain localized in the deep tissues occurs frequently in complex regional pain syndrome (CRPS). In addition, hyperalgesia to blunt pressure over muscles is common in CRPS, but it often appears in limb pain of other origin as well. Considering that 3-phase bone scintigraphy (TPBS) reveals periarticular enhanced bone metabolism in CRPS, joint-associated hyperalgesia to blunt pressure might be a more specific finding than hyperalgesia over muscles. In 34 patients with upper limb pain (18 CRPS, 16 non-CRPS; diagnosed in accordance to the Budapest criteria) and in 18 healthy controls, pressure-pain thresholds (PPT) were assessed bilaterally over the thenar (PPTThenar), the metacarpophalangeal (PPTMCP), and the proximal interphalangeal (PPTPIP) joints using a pressure algometer (Somedic, Sweden). Beforehand, all patients had received TPBS for diagnostic purposes independently of the study. Region-of-interest (ROI) ratios (mineralization phase) for the MCP and PIP, excluding fracture sites, were correlated with the PPT. In CRPS, all ROI ratios were significantly increased and all PPT of the affected hand were decreased compared to non-CRPS (PPTThenar: 243±150kPa vs 358±197kPa, PPTMCP: 80±67kPa vs 159±93kPa, PPTPIP: 80±56kPa vs 184±110kPa; PPain. Published by Elsevier B.V. All rights reserved.

Respiratory muscle stretch gymnastics in patients with post coronary artery bypass grafting pain : Impact on respiratory muscle function, activity, mood and exercise capacity

OpenAIRE

會田, 信子; 渋谷, 優子; 吉野, 克樹; Komoda, Masaji; 井上, 智子

2002-01-01

A new rehabilitation (New-RH) program including respiratory muscle stretch gymnastics (RMSG) was developed to alleviate post-coronary artery bypass grafting pain (PCP). Effects on respiratory muscle function, pain, activities of daily living (ADL), mood and exercise capacity were investigated. Subjects were 16 consecutive patients undergoing median full sternotomy coronary artery bypass grafting (CABG), and were randomly divided into equal New-RH (S-group) and conventional therapy (C-group) g...

Prevalence of and referred pain from myofascial trigger points in the forearm muscles in patients with lateral epicondylalgia.

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Fernández-Carnero, Josué; Fernández-de-Las-Peñas, César; de la Llave-Rincón, Ana Isabel; Ge, Hong-You; Arendt-Nielsen, Lars

2007-05-01

Referred pain and pain characteristics evoked from the extensor carpi radialis brevis, extensor carpi radialis longus, extensor digitorum communis, and brachioradialis muscles was investigated in 20 patients with lateral epicondylalgia (LE) and 20-matched controls. Both groups were examined for the presence of myofascial trigger points (TrPs) in a blinded fashion. The quality and location of the evoked referred pain, and the pressure pain threshold (PPT) at the lateral epicondyle on the right upper extremity (symptomatic side in patients, and dominant-side on controls) were recorded. Several lateral elbow pain parameters were also evaluated. Within the patient group, the elicited referred pain by manual exploration of 13 out of 20 (65%) extensor carpi radialis brevis muscles, 12/20 (70%) extensor carpi radialis longus muscles, 10/20 (50%) brachioradialis muscles, and 5/20 (25%) extensor digitorum communis muscles, shares similar pain patterns as their habitual lateral elbow and forearm pain. The mean number of muscles with TrPs for each patient was 2.9 [95% confidence interval (CI) 1,4] of which 2 (95% CI 1,3) were active, and 0.9 (95% CI 0,2) were latent TrPs. Control participants only had latent TrPs (mean: 0.4; 95% CI 0,2). TrP occurrence between the 2 groups was significantly different for active TrPs (P0.05). The referred pain pattern was larger in patients than in controls, with pain referral to the lateral epicondyle (proximally) and to the dorso-lateral aspect of the forearm in the patients, and confined to the dorso-lateral aspect of the forearm in the controls. Patients with LE showed a significant (Plateral epicondyle was negatively correlated with both the total number of TrPs (rs=-0.63; P=0.003) and the number of active TrPs (rs=-0.5; P=0.02): the greater the number of active TrPs, the lower the PPT at the lateral epicondyle. Our results suggest that in patients with LE, the evoked referred pain and its sensory characteristics shared similar patterns

In vitro quantification of strain patterns in the craniofacial skeleton due to masseter and temporalis activities.

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Maloul, Asmaa; Regev, Eran; Whyne, Cari M; Beek, Marteen; Fialkov, Jeffrey A

2012-09-01

Many complications in craniofacial surgery can be attributed to a lack of characterization of facial skeletal strain patterns. This study aimed to delineate human midfacial strain patterns under uniform muscle loading. The left sides of 5 fresh-frozen human cadaveric heads were dissected of all soft tissues except the temporalis and masseter muscles. Tensile forces were applied to the free mandibular ends of the muscles. Maxillary alveolar arches were used to restrain the skulls. Eight strain gauges were bonded to the surface of the midface to measure the strain under single muscle loading conditions (100 N). Maxillary strain gauges revealed a biaxial load state for both muscles. Thin antral bone experienced high maximum principal tensile strains (maximum of 685.5 με) and high minimum principal compressive strains (maximum of -722.44 με). Similar biaxial patterns of lower magnitude were measured on the zygoma (maximum of 208.59 με for maximum principal strains and -78.11 με for minimum principal strains). Results, consistent for all specimens and counter to previously accepted concepts of biomechanical behavior of the midface under masticatory muscle loading, included high strain in the thin maxillary antral wall, rotational bending through the maxilla and zygoma, and a previously underestimated contribution of the temporalis muscle. This experimental model produced repeatable strain patterns quantifying the mechanics of the facial skeleton. These new counterintuitive findings underscore the need for accurate characterization of craniofacial strain patterns to address problems in the current treatment methods and develop robust design criteria.

Muscle activation timing and balance response in chronic lower back pain patients with associated radiculopathy.

Science.gov (United States)

Frost, Lydia R; Brown, Stephen H M

2016-02-01

Patients with chronic low back pain and associated radiculopathy present with neuromuscular symptoms both in their lower back and down their leg; however, investigations of muscle activation have so far been isolated to the lower back. During balance perturbations, it is necessary that lower limb muscles activate with proper timing and sequencing along with the lower back musculature to efficiently regain balance control. Patients with chronic low back pain and radiculopathy and matched controls completed a series of balance perturbations (rapid bilateral arm raise, unanticipated and anticipated sudden loading, and rapid rise to toe). Muscle activation timing and sequencing as well as kinetic response to the perturbations were analyzed. Patients had significantly delayed lower limb muscle activation in rapid arm raise trials as compared to controls. In sudden loading trials, muscle activation timing was not delayed in patients; however, some differences in posterior chain muscle activation sequencing were present. Patients demonstrated less anterior-posterior movement in unanticipated sudden loading trials, and greater medial-lateral movement in rise to toe trials. Patients with low back pain and radiculopathy demonstrated some significant differences from control participants in terms of muscle activation timing, sequencing, and overall balance control. The presence of differences between patients and controls, specifically in the lower limb, indicates that radiculopathy may play a role in altering balance control in these patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effect of different exercise programs on cervical flexor muscles dimensions in patients with chronic neck pain.

Science.gov (United States)

Javanshir, Khodabakhsh; Amiri, Mohsen; Mohseni Bandpei, Mohammad Ali; De las Penas, Cesar Fernandez; Rezasoltani, Asghar

2015-01-01

The effect of different exercise programs on cervical flexor muscles dimensions in patients with chronic neck pain is yet to be demonstrated. The purpose of this study was to assess the effect of two exercise programs; craniocervical flexion (CCF) and cervical flexion (CF), on flexor muscles dimensions in patients with chronic neck pain. Following ethical approval, 60 patients were randomly assigned into either a CCF group or a CF group. Patients in the CCF group were given CCF exercises and those in the CF group received CF exercises. All patients received interventions for a period of ten weeks. Pain intensity and functional disability were assessed using numerical pain rate scale and neck disability index, respectively. Dimensions of longus colli (LC) and sternoclidomastoid (SCM) muscles were measured using ultrasonography (US). All measurements were taken before and after interventions. Following intervention, the CCF group demonstrated a significant increase in LC muscle dimensions including cross sectional area, width and thickness compared with the CF group. A statistically significant increase was found on SCM thickness in the CF group. Following intervention, SCM thickness measurement in the CCF group showed no significant changes. Statistically significant decrease on pain intensity and disability were also found in both groups. Present findings demonstrated that craniocervical flexion program which specifically recruiting deep cervical flexor muscles increased LC muscle dimension significantly and CF program as an endurance training program increased SCM thickness.

[Etiological analysis and significance of anterior knee pain induced by gluteal muscles contracture].

Science.gov (United States)

Zhao, Gang; Liu, Yu-jie; Wang, Jun-liang; Qi, Wei; Qu, Feng; Yuan, Bang-tuo; Wang, Jiang-tao; Shen, Xue-zhen; Liu, Yang; Zhu, Juan-li

2014-12-01

To explore causes of gluteal muscle contracture induced anterior knee pain and curative effect of arthroscopic release. From March 2002 to August 2013,36 patients with gluteal muscle contracture induced anterior knee pain were treated, including 15 males, 21 females, aged from 9 to 40 years old with an average (18.7±7.2) years old; the courses of diseases ranged from 4 to 30 years. The clinical manifestations involved limited to symmelia, positive Ober sign, buttocks touch contracture belts, knee and patella slide to lateral when doing squat activities. All patients were performed gluteal muscle contracture release under arthroscopic. Postoperative complications were observed, Kujala scoring before and after operation was used for compare curative effect. All patients were followed up with an average of 29 months. The incision were healed well, and no complications were occurred. Postoperative Kujala score were improved more than preoperative. Gluteal muscle contracture release could alleviate hypertension of lateral patella, and palys an important role in preventing patellofemoral arthritis.

Placebo effect of an inert gel on experimentally induced leg muscle pain

Directory of Open Access Journals (Sweden)

James G Hopker

2010-11-01

Full Text Available James G Hopker1, Abigail J Foad2, Christopher J Beedie2, Damian A Coleman2, Geoffrey Leach11Centre for Sports Studies, University of Kent, Chatham, Kent, UK; 2Department of Sports Science, Tourism and Leisure, Canterbury Christ Church University, Canterbury, Kent, UKPurpose: This study examined the therapeutic effects of an inert placebo gel on experimentally induced muscle pain in a sports therapy setting. It aimed to investigate the degree to which conditioned analgesia, coupled with an expectation of intervention, was a factor in subsequent analgesia.Methods: Participants were sixteen male and eight female sports therapy students at a UK University. With institutional ethics board approval and following informed consent procedures, each was exposed to pain stimulus in the lower leg in five conditions, ie, conditioning, prebaseline, experimental (two placebo gel applications, and postbaseline. In conditioning trials, participants identified a level of pain stimulus equivalent to a perceived pain rating of 6/10. An inert placebo gel was then applied to the site with the explicit instruction that it was an analgesic. Participants were re-exposed to the pain stimulus, the level of which, without their knowledge, had been decreased, creating the impression of an analgesic effect resulting from the gel. In experimental conditions, the placebo gel was applied and the level of pain stimulus required to elicit a pain rating of 6/10 recorded.Results: Following application of the placebo gel, the level of pain stimulus required to elicit a pain rating of 6/10 increased by 8.2%. Application of the placebo gel significantly decreased participant’s perceptions of muscle pain (P = 0.001.Conclusion: Subjects’ experience and expectation of pain reduction may be major factors in the therapeutic process. These factors should be considered in the sports therapeutic environment.Keywords: conditioning, expectation, perception, positive belief, sports therapy

Effect of experimental stress in 2 different pain conditions affecting the facial muscles.

Science.gov (United States)

Woda, Alain; L'heveder, Gildas; Ouchchane, Lemlih; Bodéré, Céline

2013-05-01

Chronic facial muscle pain is a common feature in both fibromyalgia (FM) and myofascial (MF) pain conditions. In this controlled study, a possible difference in the mode of deregulation of the physiological response to a stressing stimulus was explored by applying an acute mental stress to FM and MF patients and to controls. The effects of the stress test were observed on pain, sympathetic variables, and both tonic and reflex electromyographic activities of masseteric and temporal muscles. The statistical analyses were performed through a generalized linear model including mixed effects. Painful reaction to the stressor was stronger (P < .001) and longer (P = .011) in FM than in MF independently of a higher pain level at baseline. The stress-induced autonomic changes only seen in FM patients did not reach significance. The electromyographic responses to the stress test were strongest for controls and weakest for FM. The stress test had no effect on reflex activity (area under the curve [AUC]) or latency, although AUC was high in FM and latencies were low in both pain groups. It is suggested that FM is characterized by a lower ability to adapt to acute stress than MF. This study showed that an acute psychosocial stress triggered several changes in 2 pain conditions including an increase in pain of larger amplitude in FM than in MF pain. Similar stress-induced changes should be explored as possible mechanisms for differentiation between dysfunctional pain conditions. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

Can Fear, Pain, and Muscle Tension Discriminate Vaginismus from Dyspareunia/Provoked Vestibulodynia? Implications for the New DSM-5 Diagnosis of Genito-Pelvic Pain/Penetration Disorder.

Science.gov (United States)

Lahaie, Marie-Andrée; Amsel, Rhonda; Khalifé, Samir; Boyer, Stephanie; Faaborg-Andersen, Marie; Binik, Yitzchak M

2015-08-01

Fear has been suggested as the crucial diagnostic variable that may distinguish vaginismus from dyspareunia. Unfortunately, this has not been systematically investigated. The primary purpose of this study, therefore, was to investigate whether fear as evaluated by subjective, behavioral, and psychophysiological measures could differentiate women with vaginismus from those with dyspareunia/provoked vestibulodynia (PVD) and controls. A second aim was to re-examine whether genital pain and pelvic floor muscle tension differed between vaginismus and dyspareunia/PVD sufferers. Fifty women with vaginismus, 50 women with dyspareunia/PVD, and 43 controls participated in an experimental session comprising a structured interview, pain sensitivity testing, a filmed gynecological examination, and several self-report measures. Results demonstrated that fear and vaginal muscle tension were significantly greater in the vaginismus group as compared to the dyspareunia/PVD and no-pain control groups. Moreover, behavioral measures of fear and vaginal muscle tension were found to discriminate the vaginismus group from the dyspareunia/PVD and no-pain control groups. Genital pain did not differ significantly between the vaginismus and dyspareunia/PVD groups; however, genital pain was found to discriminate both clinical groups from controls. Despite significant statistical differences on fear and vaginal muscle tension variables between women suffering from vaginismus and dyspareunia/PVD, a large overlap was observed between these conditions. These findings may explain the great difficulty health professionals experience in attempting to reliably differentiate vaginismus from dyspareunia/PVD. The implications of these data for the new DSM-5 diagnosis of Genito-Pelvic Pain/Penetration Disorder are discussed.

A randomized controlled trial on the long-term effects of proprioceptive neuromuscular facilitation training, on pain-related outcomes and back muscle activity, in patients with chronic low back pain.

Science.gov (United States)

Areeudomwong, Pattanasin; Wongrat, Witchayut; Neammesri, Nertnapa; Thongsakul, Thanaporn

2017-09-01

The role of exercise therapy in improving pain-related clinical outcomes and trunk muscle activity in patients with chronic low back pain (CLBP) has been widely reported. There is little information on the effect of proprioceptive neuromuscular facilitation (PNF) training in patients with CLBP. The purpose of the present study was therefore to investigate the persistence of the effects of PNF training on pain intensity, functional disability, patient satisfaction, health-related quality of life (HRQOL) and lower back muscle activity in patients with CLBP. Forty-two participants with CLBP were randomly assigned either to 4-week PNF training or to a control group receiving a Low back pain educational booklet. Pain-related outcomes, including pain intensity, functional disability, patient satisfaction, HRQOL and lumbar erector spinae (LES) muscle activity, were measured before and after the intervention, and at a follow-up session 12 weeks after the last intervention session. Compared with the control group, after undergoing a 4-week PNF training intervention, participants showed a significant reduction in pain intensity and functional disability, and improved patient satisfaction and HRQOL (p pain-related outcomes, and increases lower back muscle activity in patients with CLBP. Copyright © 2016 John Wiley & Sons, Ltd.

Immediate effects of Graston Technique on hamstring muscle extensibility and pain intensity in patients with nonspecific low back pain

OpenAIRE

Moon, Jong Hoon; Jung, Jin-Hwa; Won, Young Sik; Cho, Hwi-Young

2017-01-01

[Purpose] The purpose of this study was to analyze the effect of Graston Technique on hamstring extensibility and pain intensity in patients with nonspecific low back pain. [Subjects and Methods] Twenty-four patients with nonspecific low back pain (27?46 years of age) enrolled in the study. All participants were randomly assigned to one of two groups: Graston technique group (n=12) and a static stretching group (n=12). The Graston Technique was used on the hamstring muscles of the experimenta...

Effect of stimulus parameters and contraction level on inhibitory responses in human jaw-closing muscles: Implications for contingent stimulation

DEFF Research Database (Denmark)

Jadidi, F; Wang, K; Arendt-Nielsen, Lars

2009-01-01

  Objective: Examine the effect of stimulus duration as well as stimulus intensity and level of muscle contraction on the inhibitory responses in human jaw-closing muscles. Design: The inhibitory jaw-reflexes, ES1 and ES2, were recorded in the surface electromyogram (EMG) of masseter and temporal...

Effects of experimental muscle pain on shoulder-abduction force steadiness and muscle activity in healthy subjects

DEFF Research Database (Denmark)

Bandholm, Thomas Quaade; Rasmussen, Lars; Aagaard, Per

2007-01-01

We previously demonstrated that the steadiness of shoulder abduction is reduced in patients with subacromial impingement syndrome (SIS), which might be related to shoulder pain associated with the SIS. The aim of the present study was to examine the acute effects of experimental shoulder muscle p...

Changes in the main masticatory muscles in CT after mandibular condyle fracture

Energy Technology Data Exchange (ETDEWEB)

Raustia, A.M. (Oulu Univ. Central Hospital (Finland). Dept. of Prosthodontics and Stomatognathic Physiology); Oikarinen, K.S. (Oulu Univ. Central Hospital (Finland). Dept. of Oral and Maxillofacial Surgery); Pyhtinen, J. (Oulu Univ. Central Hospital (Finland). Dept. of Diagnostic Radiology)

1990-11-01

The aim was to study changes in the main masticatory muscles after mandibular condyle fracture as seen by CT, comparing the densities and sizes of the masseter, medial pterygoid and lateral pterygoid muscles on the fractured side with those on the non-fractured side. More or less permanent muscular changes are detectable several years after the accident, especially in the lateral pterygoid muscle, which is attached to the condylar head. This muscle was statistically significantly smaller (p<0,001) on the fractured side. Examination of the masticatory muscles immediately after the fracture and at intervals afterwards could reveal more about the pathogenesis of the changes in these muscles. (orig.).

Does experimental low back pain change posteroanterior lumbar spinal stiffness and trunk muscle activity? A randomized crossover study.

Science.gov (United States)

Wong, Arnold Y L; Parent, Eric C; Prasad, Narasimha; Huang, Christopher; Chan, K Ming; Kawchuk, Gregory N

2016-05-01

While some patients with low back pain demonstrate increased spinal stiffness that decreases as pain subsides, this observation is inconsistent. Currently, the relation between spinal stiffness and low back pain remains unclear. This study aimed to investigate the effects of experimental low back pain on temporal changes in posteroanterior spinal stiffness and concurrent trunk muscle activity. In separate sessions five days apart, nine asymptomatic participants received equal volume injections of hypertonic or isotonic saline in random order into the L3-L5 interspinous ligaments. Pain intensity, spinal stiffness (global and terminal stiffness) at the L3 level, and the surface electromyographic activity of six trunk muscles were measured before, immediately after, and 25-minute after injections. These outcome measures under different saline conditions were compared by generalized estimating equations. Compared to isotonic saline injections, hypertonic saline injections evoked significantly higher pain intensity (mean difference: 5.7/10), higher global (mean difference: 0.73N/mm) and terminal stiffness (mean difference: 0.58N/mm), and increased activity of four trunk muscles during indentation (Ppain subsided. While previous clinical research reported inconsistent findings regarding the association between spinal stiffness and low back pain, our study revealed that experimental pain caused temporary increases in spinal stiffness and concurrent trunk muscle co-contraction during indentation, which helps explain the temporal relation between spinal stiffness and low back pain observed in some clinical studies. Our results substantiate the role of spinal stiffness assessments in monitoring back pain progression. Copyright © 2016 Elsevier Ltd. All rights reserved.

Do Psychosocial Factors Predict Muscle Strength, Pain, or Physical Performance in Patients With Knee Osteoarthritis?

Science.gov (United States)

Baert, Isabel A C; Meeus, Mira; Mahmoudian, Armaghan; Luyten, Frank P; Nijs, Jo; Verschueren, Sabine M P

2017-09-01

The aim of this study was to examine the relationship of psychosocial factors, namely, pain catastrophizing, kinesiophobia, and maladaptive coping strategies, with muscle strength, pain, and physical performance in patients with knee osteoarthritis (OA)-related symptoms. A total of 109 women (64 with knee OA-related symptoms) with a mean age of 65.4 years (49-81 years) were recruited for this study. Psychosocial factors were quantified by the Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia, and Pain Coping Inventory. Clinical features were assessed using isometric and isokinetic knee muscle strength measurements, visual analog scale, Western Ontario and McMaster Universities Osteoarthritis Index, and functional tests. Associations were examined using correlation and regression analysis. In knee OA patients, pain catastrophizing, kinesiophobia, and coping strategy explained a significant proportion of the variability in isometric knee extension and flexion strength (6.3%-9.2%), accounting for more overall variability than some demographic and medical status variables combined. Psychosocial factors were not significant independent predictors of isokinetic strength, knee pain, or physical performance. In understanding clinical features related to knee OA, such as muscle weakness, pain catastrophizing, kinesiophobia, and coping strategy might offer something additional beyond what might be explained by traditional factors, underscoring the importance of a biopsychosocial approach in knee OA management. Further research on individual patient characteristics that mediate the effects of psychosocial factors is, however, required in order to create opportunities for more targeted, personalized treatment for knee OA.

The influence of isometric exercises of the quadriceps muscle on young female patients with anterior knee pain

Directory of Open Access Journals (Sweden)

Jacek Wilczyński

2015-10-01

Full Text Available Introduction: Anterior knee pain is a disease associated with abnormalities in the patellofemoral joint. It is a common reason for seeking advice from an orthopaedist. This problem is characterised by chronic pain in the anterior part of one or both knees. This issue often affects women, especially at a young age. The effect of this ailment is deterioration of the quality of life. This dysfunction significantly reduces abilities, and often prevents the performance of daily activities. Pain usually occurs during physical activity, but may also be accompanied by prolonged immobilisation of the knee joint. In defining the type of patellofemoral instability, orthopaedists use magnetic resonance imaging, arthroscopy, ultrasonography, and X-ray examination. A relatively effective method of treatment of pain in the patellofemoral joint is through isometric exercises of the quadriceps. They increase the strength of the quadriceps femoris muscle and reduce instability in the patellofemoral joint. Aim of the research: To evaluate the effectiveness of isometric exercises of the quadriceps muscle on young female patients with anterior knee pain. Material and methods : The study involved 30 women aged 13–44 years (mean age: 26.8 years, who had been diagnosed with pain in the front of the knee. Results and conclusions: Isometric exercises of the quadriceps muscle are an effective method of reducing anterior knee pain. Isometric exercises have a beneficial influence on improving physical activity, including performing basic activities of daily living. Student’s t distribution showed, that isometric exercises of the quadriceps muscle reduce pain at the front of the knee. Kruskal-Wallis test confirmed a significant reduction of anterior knee pain.

Muscle-tendon related pain in 100 patients with hip dysplasia: prevalence and associations with self-reported hip disability and muscle strength

DEFF Research Database (Denmark)

Jacobsen, Julie Sandell

2017-01-01

dysplasia. The secondary aim was to test if muscle-tendon related pain is linearly associated to self-reported hip disability and muscle strength in patients with hip dysplasia. Materials and methods One hundred patients (17 men) with a mean age of 29+9 years were included. Clinical entity approach...

Clinimetric evaluation of methods to measure muscle functioning in patients with non-specific neck pain: a systematic review.

NARCIS (Netherlands)

Koning, C.H. de; Heuvel, S.P. van den; Staal, J.B.; Smits-Engelsman, B.C.M.; Hendriks, E.J.M.

2008-01-01

BACKGROUND: Neck pain is a significant health problem in modern society. There is evidence to suggest that neck muscle strength is reduced in patients with neck pain. This article provides a critical analysis of the research literature on the clinimetric properties of tests to measure neck muscle

Low intensity laser therapy and functional orthopedics contribution in pain and temporo mandibular dysfunction treatment

International Nuclear Information System (INIS)

Lollato, Renata Fronzaglia

2003-01-01

Temporo Mandibular Dysfunction (TMD) is a term used to describe disorders which involve temporomandibular joint (TMJ), masticatory muscles, and associated structures, isolatedly or not, whose most frequent symptoms pain. Its etiology involve controversies, and among risk factors is Class 11 malocclusion. A lot of techniques are used for TMD treatment, and the most recent are Low Intensity Laser Therapy (LILT) and Functional Orthopedics (FO). The aim of this study was to evaluate pain and buccal mobility in subjects with Class II malocclusion and TMD symptoms, treated with LILT and FO associated or not. Eighteen subjects were selected and divided in three groups. Group 1 was treated with LILT, λ = 780 nm, 70 mW, 15 J/cm 2 per point, in six sessions during two weeks. The application was in three points around the TMJ and in masticatory muscles: masseter, temporalis, sternomastoid and trapezius, on both sides when there was pain. Palpation was made before and five minutes after application and subjects answered a questionnaire with a score for pain evaluation. Group 2 received functional orthopedics aparatology Planas Indirect Composed Plates, and was evaluated once a week during two weeks, after palpation and following the same score as group 1. Group 3 received both therapies at the same time, and the first application coincided with the aparatology installation. The evaluation followed the parameters of group 1. The results were statically analyzed , and in general form did not show significant differences. There was remission of pain symptoms in ali of the groups, and group 3 showed more rapidly results. This fact leaded us to a conclusion that the association of the LILT with FO was the best treatment for the pain symptoms remission in TMD. (author)

Non-specific esterases and esterproteases in masticatory muscles from the muscular dystrophic mouse

DEFF Research Database (Denmark)

Kirkeby, S; Moe, D; Vilmann, H

1989-01-01

With the aid of histochemical and electrophoretic techniques activities for esterase and esterprotease were investigated in the digastric and masseter muscles from normal and dystrophic mice. The substrates used were alpha-naphthyl acetate and N-acetyl-L-alanine alpha-naphthyl ester. According...

Efficacy of Rhus coriaria (sumac) juice in reducing muscle pain during aerobic exercise.

Science.gov (United States)

Alghadir, A H; Gabr, S A

2016-06-01

The main target of this study was to measure the influence of sumac juice drink on muscle indices and pain during an acute, intense exercise for 30 days. Forty healthy volunteers (15-25 years) were involved in aerobic exercise program for 4 weeks. Participants ingested sumac juice or placebo drink twice daily for 30 days. All participants were subjected for the evaluation of pain and estimation of serum: creatine kinase (CK), lactic acid dehydrogenase (LDH), troponin I, hydroxyproline (hyp), total antioxidant capacity (TAC), and in vitro antioxidant activity of sumac juice using pre-validated visual analog scale, colorimetric and immunoassays. The participants of both groups, placebo and sumac, showed an increment in pain scores both during exercise and post-exercise intervals. However, the sumac juice group showed a significant smaller increase in the pain scores compared to the placebo group. Participants in the sumac juice group were more willing to use the drink in the future. They achieved a higher satisfaction of sumac juice in ameliorating and the reduction of pain. Also, the sumac group showed a significant enhancement in the level of CK, LDH, troponin I, hyp, along with significant increase in serum (TAC) compared to the placebo group. The protective activity of muscle may relate to the antioxidant activity of phenolic component(s) in sumac juice as measured by 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging (87.9%) and β-carotene-linoleic acid (68.7%) assays. These data suggest that oral administration of sumac juice may have a beneficial effect on muscle performance among athletes.

Comparison of the electrical activity of trunk core muscles and knee muscles in subjects with and without patellofemoral pain syndrome during gait

Directory of Open Access Journals (Sweden)

Raheleh Dorosti

2017-10-01

Conclusion: It seems that electromyographic activities of some of core muscles in patients with patellofemoral pain syndrome in comparison with healthy subjects are different. However, there was no differences in electromyographic activities in some of the muscles around the knee between patients and healthy subjects.

[Influence of the occlusal interference time on masticatory muscle mechanical hyperalgesia in rats].

Science.gov (United States)

Liu, Cun-rui; Xu, Xiao-xiang; Cao, Ye; Xie, Qiu-fei

2016-02-18

To investigate the relationship between the removal time of 0.2 mm occlusal interference and the recovery of masticatory muscle mechanical hyperalgesia in rats. Forty male Sprague-Dawley rats (200-220 g) were randomly assigned to eight groups, with five rats in each group: (1) naive group: these rats were anesthetized and their mouths were forced open for about 5 min (the same duration as the other groups), but restorations were not applied; (2) sham-occlusal interference control group: bands were bonded to the right maxillary first molars which did not interfere with occlusion; (3)occlusal interference group: 0.2 mm thick crowns were bonded to the right maxillary first molars; (4) 2, 3, 4, 5, and 6 d removal of occlusal interference groups: 0.2 mm thick crowns were bonded to the right maxillary first molars and removed on days 2, 3, 4, 5, and 6. The naive group and sham-occlusal interference control group were control groups. The other groups were experimental groups. Bilateral masticatory muscle mechanical withdrawal thresholds were tested on pre-application days 1, 2, and 3, and on post-application days 1, 3, 5, 7, 10, 14, 21 and 28. The rats were weighed on pre-application day 1 and on post-application days 1, 2, 3, 4, 5, 6, and 7. Between the naive group and the sham-occlusal interference control group, there was no significant difference in the masticatory muscle mechanical withdrawal threshold of bilateral temporalis and masseters at each time point. No significant difference was detected between the contralateral side and ipsilateral side in experimental groups (P>0.05). In the 2, 3, 4, and 5 d removal of occlusal interference groups, the masticatory muscle mechanical withdrawal thresholds decreased after occlusal interference and increased after removal of the crowns and recovered to the baseline on days 7, 10, 14, and 14, respectively [the masticatory muscle mechanical withdrawal thresholds of right masseter muscle were (137.46 ± 2.08) g, (139.02 ± 2

Modulation of jaw muscle spindle afferent activity following intramuscular injections with hypertonic saline.

Science.gov (United States)

Ro, J Y; Capra, N F

2001-05-01

Transient noxious chemical stimulation of small diameter muscle afferents modulates jaw movement-related responses of caudal brainstem neurons. While it is likely that the effect is mediated from the spindle afferents in the mesencephalic nucleus (Vmes) via the caudally projecting Probst's tract, the mechanisms of pain induced modulations of jaw muscle spindle afferents is not known. In the present study, we tested the hypothesis that jaw muscle nociceptors gain access to muscle spindle afferents in the same muscle via central mechanisms and alter their sensitivity. Thirty-five neurons recorded from the Vmes were characterized as muscle spindle afferents based on their responses to passive jaw movements, muscle palpation, and electrical stimulation of the masseter nerve. Each cell was tested by injecting a small volume (250 microl) of either 5% hypertonic and/or isotonic saline into the receptor-bearing muscle. Twenty-nine units were tested with 5% hypertonic saline, of which 79% (23/29) showed significant modulation of mean firing rates (MFRs) during one or more phases of ramp-and-hold movements. Among the muscle spindle primary-like units (n = 12), MFRs of 4 units were facilitated, five reduced, two showed mixed responses and one unchanged. In secondary-like units (n = 17), MFRs of 9 were facilitated, three reduced and five unchanged. Thirteen units were tested with isotonic saline, of which 77% showed no significant changes of MFRs. Further analysis revealed that the hypertonic saline not only affected the overall output of muscle spindle afferents, but also increased the variability of firing and altered the relationship between afferent signal and muscle length. These results demonstrated that activation of muscle nociceptors significantly affects proprioceptive properties of jaw muscle spindles via central neural mechanisms. The changes can have deleterious effects on oral motor function as well as kinesthetic sensibility.

Muscle injections with lidocaine improve resting fatigue and pain in patients with chronic fatigue syndrome

Directory of Open Access Journals (Sweden)

Staud R

2017-06-01

Full Text Available Roland Staud,1 Taylor Kizer,1 Michael E Robinson2 1Department of Medicine, College of Medicine, 2Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA Objective: Patients with chronic fatigue syndrome (CFS complain of long-lasting fatigue and pain which are not relieved by rest and worsened by physical exertion. Previous research has implicated metaboreceptors of muscles to play an important role for chronic fatigue and pain. Therefore, we hypothesized that blocking impulse input from deep tissues with intramuscular lidocaine injections would improve not only the pain but also fatigue of CFS patients. Methods: In a double-blind, placebo-controlled study, 58 CFS patients received 20 mL of 1% lidocaine (200 mg or normal saline once into both trapezius and gluteal muscles. Study outcomes included clinical fatigue and pain, depression, and anxiety. In addition, mechanical and heat hyperalgesia were assessed and serum levels of lidocaine were obtained after the injections. Results: Fatigue ratings of CFS patients decreased significantly more after lidocaine compared to saline injections (p = 0.03. In contrast, muscle injections reduced pain, depression, and anxiety (p < 0.001, but these changes were not statistically different between lidocaine and saline (p > 0.05. Lidocaine injections increased mechanical pain thresholds of CFS patients (p = 0.04 but did not affect their heat hyperalgesia. Importantly, mood changes or lidocaine serum levels did not significantly predict fatigue reductions. Conclusion: These results demonstrate that lidocaine injections reduce clinical fatigue of CFS patients significantly more than placebo, suggesting an important role of peripheral tissues for chronic fatigue. Future investigations will be necessary to evaluate the clinical benefits of such interventions. Keywords: muscle injections, lidocaine, metaboreceptor, chronic fatigue 

Effects of Flotation-REST on Muscle Tension Pain

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Anette Kjellgren

2001-01-01

Full Text Available The purpose of the present study was to investigate whether the floating form of the restricted environmental stimulation technique (REST may be applied within the field of pain relief. Flotation-REST consists of a procedure whereby an individual is immersed in a tank filled with water of an extremely high salt concentration. Thirty-seven patients (14 men and 23 women suffering from chronic pain consisting of aching muscles in the neck and back area participated in the study. They were randomly assigned to either a control group (17 participants or an experimental group (20 participants. The experimental group received nine opportunities to use the flotation-REST technique in the water tank over a three-week period. The results indicated that the most severe perceived pain intensity was significantly reduced, whereas low perceived pain intensity was not influenced by the floating technique. Further, the results indicated that circulating levels of the noradrenaline metabolite 3-methoxy-4-hydroxyphenylethyleneglycol were reduced significantly in the experimental group but not in the control group following treatment, whereas endorphin levels were not affected by flotation. Flotation-REST treatment also elevated the participants' optimism and reduced the degree of anxiety or depression; at nighttime, patients who underwent flotation fell asleep more easily. The present findings describe possible changes, for the better, in patients presenting with chronic pain complaints.

Effects of flotation-REST on muscle tension pain.

Science.gov (United States)

Kjellgren, A; Sundequist, U; Norlander, T; Archer, T

2001-01-01

The purpose of the present study was to investigate whether the floating form of the restricted environmental stimulation technique (REST) may be applied within the field of pain relief. Flotation-REST consists of a procedure whereby an individual is immersed in a tank filled with water of an extremely high salt concentration. Thirty-seven patients (14 men and 23 women) suffering from chronic pain consisting of aching muscles in the neck and back area participated in the study. They were randomly assigned to either a control group (17 participants) or an experimental group (20 participants). The experimental group received nine opportunities to use the flotation-REST technique in the water tank over a three-week period. The results indicated that the most severe perceived pain intensity was significantly reduced, whereas low perceived pain intensity was not influenced by the floating technique. Further, the results indicated that circulating levels of the noradrenaline metabolite 3-methoxy-4-hydroxyphenylethyleneglycol were reduced significantly in the experimental group but not in the control group following treatment, whereas endorphin levels were not affected by flotation. Flotation-REST treatment also elevated the participants' optimism and reduced the degree of anxiety or depression; at nighttime, patients who underwent flotation fell asleep more easily. The present findings describe possible changes, for the better, in patients presenting with chronic pain complaints.

An overview of the management of muscle pain and injuries ...

African Journals Online (AJOL)

Sport injuries and muscle pain can occur as a result of engagement in exercise and or organized sporting activities. These injuries affect all age groups and gender. The most common types of sporting activities known to cause these injuries include jogging, cycling, volleyball, swimming and heavy weight lifting. Lack of ...

Movement does not promote recovery of motor output following acute experimental muscle pain

DEFF Research Database (Denmark)

Schabrun, Siobhan M.; Palsson, Thorvaldur Skuli; Thapa, Tribikram

2018-01-01

Objective.:  To examine the effect of motor activity on the magnitude and duration of altered corticomotor output following experimental muscle pain. Design. : Experimental, pre-post test. Setting. : University laboratory. Subjects. : Twenty healthy individuals. Methods.:  Participants were rando....... Understanding corticomotor depression in the postpain period and what factors promote recovery has relevance for clinical pain syndromes where ongoing motor dysfunction, in the absence of pain, may predispose to symptom persistence or recurrence....

Evaluation of low-level laser therapy in the treatment of masticatory muscles spasticity in children with cerebral palsy

Science.gov (United States)

Santos, Maria Teresa Botti Rodrigues; Diniz, Michele Baffi; Gouw-Soares, Sheila Cynthia; Lopes-Martins, Rodrigo Alvaro Brandão; Frigo, Lucio; Baeder, Fernando Martins

2016-02-01

Spasticity is a motor disorder frequently present in individuals with cerebral palsy (CP). This study aimed to evaluate the effect of low-level laser therapy (LLLT) on the spasticity of the masseter and anterior temporal muscle fibers in children with CP over three weeks of intermittent laser exposures. The bite force (BF) of the masticatory muscles and the amplitude of mouth opening were evaluated before and after laser irradiation in 30 children with CP. Both sides of the masseter and temporalis muscles were irradiated with low-intensity diode laser pulses of 808-nm wavelength six times over three consecutive weeks. During the subsequent three weeks of postlaser exposures, although no laser treatment was applied, the evaluation parameters were measured and recorded. A significant improvement in the amplitude of mouth opening and a decrease in the BF were observed in the weeks following LLLT (Peffective short-term therapeutic tool. This method increased the amplitude of mouth opening and decreased the muscle tonus of children with spastic CP over a time course of three weeks of intermittent laser applications.

Psychological Factors Predict Local and Referred Experimental Muscle Pain: A Cluster Analysis in Healthy Adults

Science.gov (United States)

Lee, Jennifer E.; Watson, David; Frey-Law, Laura A.

2012-01-01

Background Recent studies suggest an underlying three- or four-factor structure explains the conceptual overlap and distinctiveness of several negative emotionality and pain-related constructs. However, the validity of these latent factors for predicting pain has not been examined. Methods A cohort of 189 (99F; 90M) healthy volunteers completed eight self-report negative emotionality and pain-related measures (Eysenck Personality Questionnaire-Revised; Positive and Negative Affect Schedule; State-Trait Anxiety Inventory; Pain Catastrophizing Scale; Fear of Pain Questionnaire; Somatosensory Amplification Scale; Anxiety Sensitivity Index; Whiteley Index). Using principal axis factoring, three primary latent factors were extracted: General Distress; Catastrophic Thinking; and Pain-Related Fear. Using these factors, individuals clustered into three subgroups of high, moderate, and low negative emotionality responses. Experimental pain was induced via intramuscular acidic infusion into the anterior tibialis muscle, producing local (infusion site) and/or referred (anterior ankle) pain and hyperalgesia. Results Pain outcomes differed between clusters (multivariate analysis of variance and multinomial regression), with individuals in the highest negative emotionality cluster reporting the greatest local pain (p = 0.05), mechanical hyperalgesia (pressure pain thresholds; p = 0.009) and greater odds (2.21 OR) of experiencing referred pain compared to the lowest negative emotionality cluster. Conclusion Our results provide support for three latent psychological factors explaining the majority of the variance between several pain-related psychological measures, and that individuals in the high negative emotionality subgroup are at increased risk for (1) acute local muscle pain; (2) local hyperalgesia; and (3) referred pain using a standardized nociceptive input. PMID:23165778

Chronic pain and difficulty in relaxing postural muscles in patients with fibromyalgia and chronic whiplash associated disorders.

Science.gov (United States)

Elert, J; Kendall, S A; Larsson, B; Månsson, B; Gerdle, B

2001-06-01

To investigate if muscle tension according to the surface electromyogram (EMG) of the shoulder flexors is increased in consecutive patients with fibromyalgia (FM) or chronic whiplash associated disorders (WAD). A total of 59 consecutive patients with FM (n = 36) or chronic WAD (n = 23) performed 100 maximal isokinetic contractions combined with surface electromyography of the trapezius and infraspinatus. A randomized group of pain-free female (n = 27) subjects served as control group. Peak torque initially (Pti) and absolute and relative peak torque at endurance level (PTe, PTer) were registered as output variables, together with the EMG level of unnecessary muscle tension, i.e., the signal amplitude ratio (SAR). The patient groups had a higher level of unnecessary tension initially and at the endurance level. The patients had lower absolute output (PTi and PTe), but the relative levels (PTer) did not differ comparing all 3 groups. Subjects with FM had significantly higher body mass index (BMI) than the other groups. BMI did not influence the SAR but correlated positively with PTi. The results confirmed earlier findings that groups of patients with chronic pain have increased muscle tension and decreased output during dynamic activity compared to pain-free controls. However, the results indicated there is heterogeneity within groups of patients with the same chronic pain disorder and that not all patients with chronic pain have increased muscle tension.

Temporomandibular joint and muscle disorder-type pain and comorbid pains in a national US sample.

Science.gov (United States)

Plesh, Octavia; Adams, Sally H; Gansky, Stuart A

2011-01-01

To compare prevalences of self-reported comorbid headache, neck, back, and joint pains in respondents with temporomandibular joint and muscle disorder (TMJMD)-type pain in the 2000-2005 US National Health Interview Survey (NHIS), and to analyze these self-reported pains by gender and age for Non-Hispanic (NH) Whites (Caucasians), Hispanics, and NH Blacks (African Americans). Data from the 2000-2005 NHIS included information on gender, age, race, ethnicity, education, different common types of pain (specifically TMJMD-type, severe headache/migraine, neck, and low back pains), changes in health status, and health care utilization. Estimates and test statistics (ie, Pearson correlations, regressions, and logistic models) were conducted using SAS survey analysis and SUDAAN software that take into account the complex sample design. A total of 189,977 people (52% female and 48% males, 73% NH Whites, 12% Hispanic, 11% NH Blacks, and 4% "Other") were included. A total of 4.6% reported TMJMD-type pain, and only 0.77% overall reported it without any comorbid headache/migraine, neck, or low back pains; also 59% of the TMJMD-type pain (n = 8,964) reported ⋝ two comorbid pains. Females reported more comorbid pain than males (odds ratio [OR] = 1.41, P neck pain, 64% low back pain, and 62% joint pain. Differences in gender and race by age patterns were detected. For females, headache/migraine pain with TMJMD-type pain peaked around age 40 and decreased thereafter regardless of race/ethnicity. Neck pain continued to increase up to about age 60, with a higher prevalence for Hispanic women at younger ages, and more pronounced in males, being the highest in the non-Whites. Low back pain was higher in Black and Hispanic females across the age span, and higher among non-White males after age 60. Joint pain demonstrated similar patterns by race/ethnicity, with higher rates for Black females, and increased with age regardless of gender. TMJMD-type pain was most often associated with

Cervical-scapular muscles strength and severity of temporomandibular disorder in women with mechanical neck pain

Directory of Open Access Journals (Sweden)

Fernanda Pasinato

Full Text Available Abstract Introduction: Changes in cervical muscle function have been observed in patients with neck pain (NP and TMD. However, the relationship between TMD severity and neck muscle strength in the presence/absence of NP is unknown. Objective: To determine the prevalence of TMD in women with and without mechanical NP and assess the cervical-scapular muscle strength and its association with TMD severity. Methods: Fifteen volunteers without neck pain (CG and 14 women with mechanical neck pain (NPG took part and were selected by the Neck Disability Index. The diagnosis and severity of TMD were determined by the Research Diagnostic Criteria for TMD and Temporomandibular Index (TI, respectively. The strength of the upper trapezius muscle, and cervical flexor and extensor muscles was measured by digital hand dynamometer. Results: 64.5% of women with NP and 33.3% without NP were diagnosed with TMD (p = 0.095. The NPG showed lower strength of the cervical flexor (p = 0.044 and extensor (p=0.006 muscles, and higher TI (p = 0.038 than in the CG. It was also verified moderate negative correlation between TI and the strength of dominant (p = 0.046, r = -0.547 and non-dominant (p = 0.007, r = -0.695 upper trapezius, and cervical flexors (p = 0.023, r = -0.606 in the NPG. Conclusion: There was no difference in the prevalence of TMD in women with and without NP. However, women with NP have lower cervical muscle strength - compared to those without NP - which was associated with greater severity of TMD. Thus, in women with NP associated with TMD, it is advisable to assess and address the severity of this dysfunction and identify the cervical-scapular muscles compromise.

Neck muscle endurance and head posture: A comparison between adolescents with and without neck pain.

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Oliveira, Ana Carolina; Silva, Anabela G

2016-04-01

The main aims of this study were to compare the neck flexor and extensor endurance and forward head posture between adolescents with and without neck pain. The secondary aims were to explore potential associations between muscles endurance, head posture and neck pain characteristics and to assess intra-rater reliability of the measurements used. Adolescents with neck pain (n = 35) and age-matched asymptomatic adolescents (n = 35) had their forward head posture, neck flexor endurance and neck extensor endurance measured using clinical tests. Intra-rater reliability was also assessed. Forward head posture and neck flexor and extensor endurance tests showed moderate to almost perfect intra-rater reliability (ICC between 0.58 and 0.88). Adolescents with neck pain showed significantly less forward head posture (neck pain = 46.62 ± 4.92; asymptomatic = 44.18°± 3.64°, p > 0.05) and less neck flexor (neck pain = 24.50 ± 23.03s; asymptomatic = 35.89 ± 21.53s, p > 0.05) and extensor endurance (neck pain = 12.6.64 ± 77.94s; asymptomatic = 168.66 ± 74.77s, p > 0.05) than asymptomatic adolescents. Results suggest that changes in posture and neck muscle endurance are a feature of adolescents with neck pain. Copyright © 2015 Elsevier Ltd. All rights reserved.

Congenital muscle dystrophy and diet consistency affect mouse skull shape differently.

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Spassov, Alexander; Toro-Ibacache, Viviana; Krautwald, Mirjam; Brinkmeier, Heinrich; Kupczik, Kornelius

2017-11-01

The bones of the mammalian skull respond plastically to changes in masticatory function. However, the extent to which muscle function affects the growth and development of the skull, whose regions have different maturity patterns, remains unclear. Using muscle dissection and 3D landmark-based geometric morphometrics we investigated the effect of changes in muscle function established either before or after weaning, on skull shape and muscle mass in adult mice. We compared temporalis and masseter mass and skull shape in mice with a congenital muscle dystrophy (mdx) and wild type (wt) mice fed on either a hard or a soft diet. We found that dystrophy and diet have distinct effects on the morphology of the skull and the masticatory muscles. Mdx mice show a flattened neurocranium with a more dorsally displaced foramen magnum and an anteriorly placed mandibular condyle compared with wt mice. Compared with hard diet mice, soft diet mice had lower masseter mass and a face with more gracile features as well as labially inclined incisors, suggesting reduced bite strength. Thus, while the early-maturing neurocranium and the posterior portion of the mandible are affected by the congenital dystrophy, the late-maturing face including the anterior part of the mandible responds to dietary differences irrespective of the mdx mutation. Our study confirms a hierarchical, tripartite organisation of the skull (comprising neurocranium, face and mandible) with a modular division based on development and function. Moreover, we provide further experimental evidence that masticatory loading is one of the main environmental stimuli that generate craniofacial variation. © 2017 Anatomical Society.

Masticatory muscle pain and progressive mouth opening limitation caused by amyotrophic lateral sclerosis: a case report.

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Pang, Kang Mi; Park, Ji Woon

2015-01-01

This article reports a case of masticatory muscle pain and progressive limited mouth opening secondary to amyotrophic lateral sclerosis (ALS), popularly known as Lou Gehrig's disease. The symptoms were first mistaken as those of temporomandibular disorders, before fatty degeneration of all masticatory muscles were discovered on magnetic resonance imaging (MRI). ALS should be considered in the differential diagnosis process when the patient presents with longstanding progressive mouth opening limitation associated with pain. MRI could facilitate the diagnostic process.

IS PAIN IN ONE KNEE ASSOCIATED WITH ISOMETRIC MUSCLE STRENGTH IN THE CONTRALATERAL LIMB? - DATA FROM THE OSTEOARTHRITIS INITIATIVE (OAI)

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Steidle, E.; Wirth, W.; Glass, N.; Ruhdorfer, A.; Cotofana, S.; Eckstein, F.; Segal, N. A.

2014-01-01

Objective Knee pain and muscle weakness confer risk for knee osteoarthritis incidence and progression. The purpose of this study was to determine whether unilateral knee pain influences contralateral thigh muscle strength. Design Of 4796 Osteoarthritis Initiative participants, 224 (mean±SD age 63.9±8.9 years) cases could be matched to a control. Cases were defined as having unilateral knee pain (numerical rating scale (NRS)≥4/10; ≥infrequent pain) and one pain-free knee (NRS 0–1; ≤infrequent pain; WOMAC≤1). Controls were defined as having bilaterally pain-free knees (NRS 0–1; ≤infrequent pain; WOMAC≤1). Maximal isometric muscle strength [N] was compared between limbs in participants with unilateral pain (cases), and between pain-free limbs of cases and controls. Results Knee extensor/flexor strength in pain-free limbs of cases was lower than in bilaterally pain-free controls (−5.5%/–8.4%; p=0.043/p=0.022). Within cases, maximum extensor/flexor strength was significantly lower in the painful than in the pain-free limb (−6.4%/4.1%; pstrength in limbs without knee pain is associated with the pain status of the contralateral knee. The strength difference between unilateral pain-free cases and matched bilateral pain-free controls was similar to that between limbs in persons with unilateral knee pain. Lower strength due to contralateral knee pain might be centrally mediated. PMID:25768069

Temporal association between changes in primary sensory cortex and corticomotor output during muscle pain.

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Schabrun, S M; Jones, E; Kloster, J; Hodges, P W

2013-04-03

Integration of information between multiple cortical regions is thought to underpin the experience of pain. Yet studies tend to focus on pain related changes in discrete cortical regions. Although altered processing in the primary motor (M1) and sensory cortex (S1) is implicated in pain, the temporal relationship between these regions is unknown and may provide insight into the interaction between them. We used recordings of somatosensory-evoked potentials (SEPs) and transcranial magnetic stimulation to investigate the temporal relationship between altered excitability of the primary sensory cortex and corticomotor output during and after muscle pain induced by hypertonic saline infusion into the right first dorsal interosseous. SEPs and motor-evoked potentials (MEPs) were recorded in 12 healthy individuals. Participants reported an average pain intensity of 5.4 (0.5) on a 10-cm visual analogue scale. The area of the N20-P25-N33 complex of the SEP was reduced during and after pain, but MEP amplitudes were suppressed only after pain had resolved. Our data show that pain reduces sensory processing before motor output is altered. This temporal dispersion, coupled with the lack of correlation between pain-induced changes in S1 and M1 excitability, imply either that independent processes are involved, or that reduced excitability of S1 during acute experimental muscle pain mediates latent reductions in motor output via processes that are non-linear and potentially involve activation of a wider brain network. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Muscle Control and Non-specific Chronic Low Back Pain.

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Russo, Marc; Deckers, Kristiaan; Eldabe, Sam; Kiesel, Kyle; Gilligan, Chris; Vieceli, John; Crosby, Peter

2018-01-01

Chronic low back pain (CLBP) is the most prevalent of the painful musculoskeletal conditions. CLBP is a heterogeneous condition with many causes and diagnoses, but there are few established therapies with strong evidence of effectiveness (or cost effectiveness). CLBP for which it is not possible to identify any specific cause is often referred to as non-specific chronic LBP (NSCLBP). One type of NSCLBP is continuing and recurrent primarily nociceptive CLBP due to vertebral joint overload subsequent to functional instability of the lumbar spine. This condition may occur due to disruption of the motor control system to the key stabilizing muscles in the lumbar spine, particularly the lumbar multifidus muscle (MF). This review presents the evidence for MF involvement in CLBP, mechanisms of action of disruption of control of the MF, and options for restoring control of the MF as a treatment for NSCLBP. Imaging assessment of motor control dysfunction of the MF in individual patients is fraught with difficulty. MRI or ultrasound imaging techniques, while reliable, have limited diagnostic or predictive utility. For some patients, restoration of motor control to the MF with specific exercises can be effective, but population results are not persuasive since most patients are unable to voluntarily contract the MF and may be inhibited from doing so due to arthrogenic muscle inhibition. Targeting MF control with restorative neurostimulation promises a new treatment option. © 2017 The Authors. Neuromodulation: Technology at the Neural Interface published by Wiley Periodicals, Inc. on behalf of International Neuromodulation Society.

Comparative morphology of the muscles of mastication in the giant panda and the Asiatic black bear.

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Endo, Hideki; Taru, Hajime; Yamamoto, Masako; Arishima, Kazuyoshi; Sasaki, Motoki

2003-06-01

The morphological differences in the muscles of mastication between the giant panda (Ailuropoda melanoleuca) and the Asiatic black bear (Ursus thibetanus) were sought to confirm the adaptational strategy of these muscles in the giant panda. We measured some skull characteristics and weighed the muscles of mastication, and macroscopically observed the muscles of mastication in the two species. The noticeable differences between the two species are classified as follows: (1) The size ratio of the zygomatic width was much larger in the giant panda than in the Asiatic black bear. (2) The weight ratio of the two pterygoid muscles was also much larger in the giant panda than in the Asiatic black bear. (3) The lateral slips of the temporal muscles are thicker and stronger in the Asiatic black bear than in the giant panda. (4) The deep layer of the masseter muscle was rostrocaudally divided, and a complicated running of tendons is observed in the giant panda. (5) The two pterygoid muscles were much larger and well-developed in the giant panda than in the Asiatic black bear. The points (1) and (4) may be related to the generation of the force necessary to chew the bamboo in the giant panda. We thought that the large mass of the masseter and temporal muscles are needed in this species. In the points of (2) and (5), the two pterygoid muscles were obviously different in form and weight ratio between the two species. We suggest that the two pterygoid muscles may act as an additional force generator to dorsoventrally press and crush bamboo stems.

Cervical joint position sense in neck pain. Immediate effects of muscle vibration versus mental training interventions: a RCT.

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Beinert, K; Preiss, S; Huber, M; Taube, W

2015-12-01

Impaired cervical joint position sense is a feature of chronic neck pain and is commonly argued to rely on abnormal cervical input. If true, muscle vibration, altering afferent input, but not mental interventions, should have an effect on head repositioning acuity and neck pain perception. The aim of the present study was to determine the short-term effects of neck muscle vibration, motor imagery, and action observation on cervical joint position sense and pressure pain threshold in people with chronic neck pain. Forty-five blinded participants with neck pain received concealed allocation and were randomized in three treatment groups. A blinded assessor performed pre- and post-test measurement. Patients were recruited from secondary outpatient clinics in the southwest of Germany. Chronic, non specific neck pain patients without arm pain were recruited for this study. A single intervention session of 5 minutes was delivered to each blinded participant. Patients were either allocated to one of the following three interventions: (1) neck muscle vibration; (2) motor imagery; (3) action observation. Primary outcomes were cervical joint position sense acuity and pressure pain threshold. Repeated measures ANOVAs were used to evaluate differences between groups and subjects. Repositioning acuity displayed significant time effects for vibration, motor imagery, and action observation (all Ppain threshold demonstrated a time*group effect (P=0.042) as only vibration significantly increased pressure pain threshold (P=0.01). Although motor imagery and action observation did not modulate proprioceptive, afferent input, they nevertheless improved cervical joint position sense acuity. This indicates that, against the common opinion, changes in proprioceptive input are not prerequisite to improve joint repositioning performance. However, the short-term applications of these cognitive treatments had no effect on pressure pain thresholds, whereas vibration reduced pressure pain

Muscle power is an independent determinant of pain and quality of life in knee osteoarthritis

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OBJECTIVE: This study examined the relationships between leg muscle strength, power, and perceived disease severity in subjects with knee osteoarthritis (OA) in order to determine whether dynamic leg extensor muscle power would be associated with pain and quality of life in knee OA. METHODS: Baseli...

Are Ultrasonographic Measures of Cervical Flexor Muscles Correlated With Flexion Endurance in Chronic Neck Pain and Asymptomatic Participants?

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Ghamkhar, Leila; Kahlaee, Amir Hossein

2017-12-01

This study compared the relationship between some clinical factors and the size of neck flexors in participants with or without chronic neck pain. In this case-control study, the correlation between flexor endurance capacity as well as thickness, cross-section area, and shape ratio of longus colli/capitis and sternocleidomastoid muscles were examined in 30 patients with chronic neck pain and 30 asymptomatic participants. The patients showed lower flexor endurance (P = 0.02), smaller thickness (P = 0.03), and cross-section area (P pain. In the control group, flexor endurance was negatively correlated with longus colli shape ratio (r = -0.45, P = 0.01) but positively correlated with longus capitis thickness (r = 0.45, P = 0.01) and cross-section area (r = 0.38, P = 0.03). Neck disability and pain intensity indices were not significantly correlated with either flexor muscles endurance or size. The ultrasonographic measures of the deep neck flexor muscles and the flexor endurance test, being associated with each other, could successfully differentiate patients with chronic neck pain from asymptomatic participants. However, the endurance test scores were not correlated with self-reported disability or pain intensity indices.

Reduction of cervical and respiratory muscle strength in patients with chronic nonspecific neck pain and having moderate to severe disability.

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López-de-Uralde-Villanueva, Ibai; Sollano-Vallez, Ernesto; Del Corral, Tamara

2017-06-11

To investigate whether patients with chronic nonspecific neck pain and having moderate to severe disability have a greater cervical motor function impairment and respiratory disturbances compared with patients with chronic nonspecific neck pain having mild disability and asymptomatic subjects; and the association between these outcomes in patients with chronic nonspecific neck pain and healthy controls. Cross-sectional study, 44 patients with chronic nonspecific neck pain and 31 healthy subjects participated. The neck disability index was used to divide the patients into 2 groups: 1) mild disability group (scores between 5 and 14 points); and 2) moderate to severe disability group (scores >14 points). Cervical motor function was measured by cervical range of motion, forward head posture, neck flexor, and extensor muscle strength. Respiratory function and maximum respiratory pressures were also measured. Statistically differences were found between the patients with chronic nonspecific neck pain having a moderate to severe disability and the asymptomatic subjects for cervical and respiratory muscle strength. Comparisons between chronic nonspecific neck pain and the asymptomatic groups showed differences for all the variables, except for forward head posture. The regression model determined that strength of cervical flexion explained 36.4 and 45.6% of the variance of maximum inspiratory pressures and maximum expiratory pressures, respectively. Only the chronic nonspecific neck pain group with moderate to severe disability showed differences compared with the healthy subjects. Neck muscle strength could be a good predictor of respiratory muscle function. Implications for rehabilitation Neck pain severity could be closely associated with decreased respiratory pressure in patients with chronic nonspecific neck pain. These findings suggest a new therapeutic approach for patients with moderate to severe disability, such as respiratory muscle training. The regression

Immediate effect of occlusal contact pattern in lateral jaw position on the EMG activity in jaw-elevator muscles in humans.

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Baba, K; Yugami, K; Akishige, S; Ai, M

2000-01-01

The aim of this study was to investigate the effect of experimental alterations of nonworking-side occlusal contacts on jaw-elevator muscle activity. Individual devices were fabricated to simulate various lateral occlusal relationships. Twelve human subjects were asked to carry out submaximal lateral clenching, and electromyographic (EMG) activity of the masseter and anterior and posterior temporalis muscles was measured. Clenching in a lateral mandibular position under natural conditions induced an activity pattern with a clear dominance of the anterior and posterior temporalis muscles on the working side. Working-side dominance in the anterior temporalis was reduced moderately when an experimental nonworking-side occlusal contact was added. Dominance decreased dramatically when an experimental nonworking-side interference was added. The working-side activity in the posterior temporalis was also reduced dramatically by an experimental nonworking-side interference, but not by a nonworking-side occlusal contact. None of the experimental contact patterns had a significant effect on the masseter activity. These results suggest that the nonworking-side occlusal contacts have a significant effect on clenching-induced temporalis muscle activity.

Effect of brief daily resistance training on rapid force development in painful neck and shoulder muscles

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Jay, Kenneth; Schraefel, Mc; Andersen, Christoffer H

2013-01-01

OBJECTIVE: To determine the effect of small daily amounts of progressive resistance training on rapid force development of painful neck/shoulder muscles. METHODS: 198 generally healthy adults with frequent neck/shoulder muscle pain (mean: age 43.1 years, computer use 93% of work time, 88% women......, duration of pain 186 day during the previous year) were randomly allocated to 2- or 12 min of daily progressive resistance training with elastic tubing or to a control group receiving weekly information on general health. A blinded assessor took measures at baseline and at 10-week follow-up; participants.......05) for both training groups. Maximal muscle strength increased only ~5-6% [mean and 95% confidence interval for 2- and 12-min groups to control, respectively: 2.5 Nm (0.05-0.73) and 2.2 Nm (0.01-0.70)]. No significant differences between the 2- and 12-min groups were evident. A weak but significant...

ASSOCIATION OF KNEE PAIN WITH A REDUCTION IN THIGH MUSCLE STRENGTH – A CROSS-SECTIONAL ANALYSIS INCLUDING 4553 OSTEOARTHRITIS INITIATIVE PARTICIPANTS

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Ruhdorfer, Anja; Wirth, Wolfgang; Eckstein, Felix

2016-01-01

Objective To cross-sectionally determine the quantitative relationship of age-adjusted, sex-specific isometric knee extensor and flexor strength to patient-reported knee pain. Methods Difference of thigh muscle strength by age, and that of age-adjusted strength per unit increase on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) knee pain scale, was estimated from linear regression analysis of 4553 Osteoarthritis Initiative participants (58% women). Strata encompassing the minimal clinically important difference (MCID) in knee pain were compared to evaluate a potentially non-linear relationship between WOMAC pain levels and muscle strength. Results In Osteoarthritis Initiative participants without pain, the age-related difference in isometric knee extensor strength was −9.0%/−8.2% (women/men) per decade, and that of flexor strength was −11%/−6.9%. Differences in age-adjusted strength values for each unit of WOMAC pain (1/20) amounted to −1.9%/−1.6% for extensor and −2.5%/−1.7% for flexor strength. Differences in torque/weight for each unit of WOMAC pain ranged from −3.3 to − 2.1%. There was no indication of a non-linear relationship between pain and strength across the range of observed WOMAC values, and similar results were observed in women and men. Conclusion Each increase by 1/20 units in WOMAC pain was associated with a ~2% lower age-adjusted isometric extensor and flexor strength in either sex. As a reduction in muscle strength is known to prospectively increase symptoms in knee osteoarthritis and as pain appears to reduce thigh muscle strength, adequate therapy of pain and muscle strength is required in knee osteoarthritis patients to avoid a vicious circle of self-sustaining clinical deterioration. PMID:27836675

Neck Pain Following Cervical Laminoplasty: Does Preservation of the C2 Muscle Attachments and/or C7 Matter?

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Riew, K. Daniel; Raich, Annie L.; Dettori, Joseph R.; Heller, John G.

2013-01-01

Study Design Systematic review. Objective In patients aged 18 years or older, with cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament (OPLL), does sparing the C2 muscle attachments and/or C7-preserving cervical laminoplasty lead to reduced postoperative axial pain compared with conventional C3 to C7 laminoplasty? Do these results vary based on early active postoperative cervical motion? Methods A systematic review of the English-language literature was undertaken for articles published between 1970 and August 17, 2012. Electronic databases and reference lists of key articles were searched to identify studies evaluating C2/C3- or C7-preserving cervical laminoplasty for the treatment of cervical spondylotic myelopathy (CSM) or OPLL in adults. Studies involving traumatic onset, cervical fracture, infection, deformity, or neoplasms were excluded, as were noncomparative studies. Two independent reviewers assessed the level of evidence quality using the grading of recommendations assessment, development and evaluation (GRADE) system, and disagreements were resolved by consensus. Results We identified 11 articles meeting our inclusion criteria. Only the randomized controlled trial (RCT) showed no significant difference in late axial pain (at 12 months) when C7 spinous muscle preservation was compared with no preservation. However, seven other retrospective cohort studies showed significant pain relief in the preserved group compared with the nonpreserved group. The preservation group included those with preservation of the C7 spinous process and/or attached muscles, the deep extensor muscles, or C2 muscle attachment and/or C3 laminectomy (as opposed to laminoplasty). One study that included preservation of either the C2 or C7 posterior paraspinal muscles found that only preservation of the muscles attached to C2 resulted in reduced postoperative pain. Another study that included preservation of either the C7 spinous process or

Effects of unilateral and bilateral experimental low-back pain on trunk muscle activity during stair walking in healthy and recurrent low-back pain patients

DEFF Research Database (Denmark)

Larsen, Lars Henrik; Hirata, Rogerio Pessoto; Graven-Nielsen, Thomas

Aim To explore the trunk muscle activity in healthy and recurrent low back pain (R-LBP) patients with no present pain during stair ascent and descent before and after unilateral and bilateral experimental low back pain (LBP). Methods Twenty-five healthy controls and 25 pain-free R-LBP patients wi...... in the physical examination, but it remains unknown if the observed changes are appropriate strategies in relation to the pain condition. Acknowledgement The study was supported by CNAP, Aalborg University and UCN Department of physiotherapy, Denmark....

Pain and fear avoidance partially mediate change in muscle strength during resistance exercise in women with fibromyalgia.

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Larsson, Anette; Palstam, Annie; Löfgren, Monika; Ernberg, Malin; Bjersing, Jan; Bileviciute-Ljungar, Indre; Gerdle, Björn; Kosek, Eva; Mannerkorpi, Kaisa

2017-11-21

Resistance exercise results in health benefits in fibromyalgia. The aim of this study was to determine the factors that mediate change in muscle strength in women with fibromyalgia as a result of resistance exercise. Sixty-seven women with fibromyalgia (age range 25-64 years) were included. Tests of muscle strength and questionnaires related to pain, fear avoidance and physical activity were carried out. Multivariable stepwise regression was used to analyse explanatory factors for change and predictors for final values of knee-extension force, elbow-flexion force and hand-grip force. Change in knee-extension force was explained by fear avoidance beliefs about physical activity at baseline, together with change in pain intensity, knee-extension force at baseline, age and body mass index (BMI) (R2=0.40, p = 0.013). Change in elbow-flexion force was explained by pain intensity at baseline, together with baseline fear avoidance beliefs about physical activity, BMI and elbow-flexion force at baseline (R2 = 0.32, p = 0.043). Change in hand-grip force was explained by hand-grip force at baseline, change in pain intensity and baseline fear avoidance (R2 = 0.37, p = 0.009). Final muscle strength was predicted by the same variables as change, except pain. Pain and fear avoidance are important factors to consider in rehabilitation using resistance exercise for women with fibromyalgia.

Vestibular-evoked myogenic potentials in miniature pigs

Directory of Open Access Journals (Sweden)

Xi Shi

2016-06-01

Conclusion: The latencies and thresholds of VEMPs recorded from the neck extensor muscle and the masseter muscle appear to be comparable in normal adult Bama miniature pigs, although the amplitude recorded from the neck extensor muscle seems to be higher than that from the masseter muscle. However, because of their usually relatively superficial and easily accessible location, as well as their large volume and strong contractions, masseter muscles may be better target muscles for recording myogenic potentials.

Comparison of the effects of knee and hip and single knee muscles strengthening/ stretching exercises on pain intensity and function in athletes with patellofemoral pain syndrome

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Vahid Mazloum

2016-08-01

Full Text Available Background: Patellofemoral pain syndrome (PFPS is a common musculoskeletal condition among athletes. The evidence emphasizes on the importance of hip musculature strengthening exercises for such patients. Objective: To investigate the effects of strengthening-stretching knee muscles exercises and hip posterolateral musculature exercises in athletes with PFPS. Methods: In this clinical trial, 28 athletes with age average of 22.7±2.4 years with PFPS were allocated into conventional knee muscles exercises (CKME (n=14 and posterolateral hip muscles exercises (PHME (n=14. The subjects of both groups performed the supervised exercise protocols in 12 sessions. The Visual Analogue Scale and 6-minute walking tests were administrated respectively to evaluate pain intensity and function. The data were analyzed using Shapiro-wilk test, Independent-sample t test, and Repeated Measure ANOVA test. Findings: Demographic, pain intensity, and physical function data were similar between groups at baseline. Both groups significantly improved in pain intensity and function following a 4-week exercise program. Additionally, the athletes in PHME group had higher level of decreased pain intensity and improved function in follow-up assessment than the subjects in CKME group. Conclusion: Using hip posterolateral musculature exercises in addition to the knee conventional exercises is more effective for athletes with PFPS.

Surface electromyographic patterns of masticatory, neck, and trunk muscles in temporomandibular joint dysfunction patients undergoing anterior repositioning splint therapy.

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Tecco, Simona; Tetè, Stefano; D'Attilio, Michele; Perillo, Letizia; Festa, Felice

2008-12-01

The aim of this study was to investigate the surface electromyographic (sEMG) activity of neck, trunk, and masticatory muscles in subjects with temporomandibular joint (TMJ) internal derangement treated with anterior mandibular repositioning splints. sEMG activities of the muscles in 34 adult subjects (22 females and 12 males; mean age 30.4 years) with TMJ internal derangement were compared with a control group of 34 untreated adults (20 females and 14 males; mean age 31.8 years). sEMG activities of seven muscles (anterior and posterior temporalis, masseter, posterior cervicals, sternocleidomastoid, and upper and lower trapezius) were studied bilaterally, with the mandible in the rest position and during maximal voluntary clenching (MVC), at the beginning of therapy (T0) and after 10 weeks of treatment (T1). Paired and Student's t-tests were undertaken to determine differences between the T0 and T1 data and in sEMG activity between the study and control groups. At T0, paired masseter, sternocleidomastoid, and cervical muscles, in addition to the left anterior temporal and right lower trapezius, showed significantly greater sEMG activity (P = 0.0001; P = 0.0001; for left cervical, P = 0.03; for right cervical, P = 0.0001; P = 0.006 and P = 0.007 muscles, respectively) compared with the control group. This decreased over the remaining study period, such that after treatment, sEMG activity revealed no statistically significant difference when compared with the control group. During MVC at T0, paired masseter and anterior and posterior temporalis muscles showed significantly lower sEMG activity (P = 0.03; P = 0.005 and P = 0.04, respectively) compared with the control group. In contrast, at T1 sEMG activity significantly increased (P = 0.02; P = 0.004 and P = 0.04, respectively), but no difference was observed in relation to the control group. Splint therapy in subjects with internal disk derangement seems to affect sEMG activity of the masticatory, neck, and trunk

Effectiveness of home-based cupping massage compared to progressive muscle relaxation in patients with chronic neck pain--a randomized controlled trial.

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Lauche, Romy; Materdey, Svitlana; Cramer, Holger; Haller, Heidemarie; Stange, Rainer; Dobos, Gustav; Rampp, Thomas

2013-01-01

Chronic neck pain is a major public health problem with very few evidence-based complementary treatment options. This study aimed to test the efficacy of 12 weeks of a partner-delivered home-based cupping massage, compared to the same period of progressive muscle relaxation in patients with chronic non-specific neck pain. Patients were randomly assigned to self-directed cupping massage or progressive muscle relaxation. They were trained and asked to undertake the assigned treatment twice weekly for 12 weeks. Primary outcome measure was the current neck pain intensity (0-100 mm visual analog scale; VAS) after 12 weeks. Secondary outcome measures included pain on motion, affective pain perception, functional disability, psychological distress, wellbeing, health-related quality of life, pressure pain thresholds and adverse events. Sixty one patients (54.1±12.7 years; 73.8%female) were randomized to cupping massage (n = 30) or progressive muscle relaxation (n = 31). After treatment, both groups showed significantly less pain compared to baseline however without significant group differences. Significant effects in favor of cupping massage were only found for wellbeing and pressure pain thresholds. In conclusion, cupping massage is no more effective than progressive muscle relaxation in reducing chronic non-specific neck pain. Both therapies can be easily used at home and can reduce pain to a minimal clinically relevant extent. Cupping massage may however be better than PMR in improving well-being and decreasing pressure pain sensitivity but more studies with larger samples and longer follow-up periods are needed to confirm these results. ClinicalTrials.gov NCT01500330.

EFFECTIVENESS OF MUSCLE STRETCHING IN OCCUPATION RELATED CHRONIC MECHANICAL LOW BACK PAIN IN COMMUNITY NURSES –A SINGLE BLIND STUDY

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Khwairakpam Zhimina Devi; Sai Kumar. N; Vinod Babu. K; V.R. Ayyappan

2014-01-01

Background and Objective: Stretching of Lower Back Muscle, Hamstring and Tensor Fasciae Latae have an immediate effect on Chronic Lower Back Pain. Hence the purpose is to find the short term effect of stretching of Lower Back Muscle, Hamstring and Tensor Fasciae Latae on intensity of low back pain, flexibility and functional disability in occupation related Chronic Mechanical Low Back Pain in Community Nurses. Method: Single blind experimental study design, 40 subjects with Chronic mechani...

Changes in muscle activity and stature recovery after active rehabilitation for chronic low back pain.

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Lewis, Sandra; Holmes, Paul; Woby, Steve; Hindle, Jackie; Fowler, Neil

2014-06-01

Patients with low back pain often demonstrate elevated paraspinal muscle activity compared to asymptomatic controls. This hyperactivity has been associated with a delayed rate of stature recovery following spinal loading tasks. The aim of this study was to investigate the changes in muscle activity and stature recovery in patients with chronic low back pain following an active rehabilitation programme. The body height recovery over a 40-min unloading period was assessed via stadiometry and surface electromyograms were recorded from the paraspinal muscles during standing. The measurements were repeated after patients had attended the rehabilitation programme and again at a six-month follow-up. Analysis was based on 17 patients who completed the post-treatment analysis and 12 of these who also participated in the follow-up. By the end of the six months, patients recovered significantly more height during the unloading session than at their initial visit (ES = 1.18; P < 0.01). Greater stature recovery immediately following the programme was associated with decreased pain (r = -0.55; P = 0.01). The increased height gain after six months suggests that delayed rates of recovery are not primarily caused by disc degeneration. Muscle activity did not decrease after treatment, perhaps reflecting a period of adaptation or altered patterns of motor control. Copyright © 2014 Elsevier Ltd. All rights reserved.

The differences of brain cortical activation between superficial pain and deep pain

International Nuclear Information System (INIS)

Ikemoto, Tatsunori; Ushida, Takahiro; Taniguchi, Shinichirou; Tani, Toshikazu; Morio, Kazuo; Sasaki, Toshikazu; Tanaka, Shigeki

2006-01-01

Using functional magnetic resonance imaging (FMRI) technology, we investigated the difference of pain related brain cortical activation derived from noxious stimulation to the skin and muscular tissue. Ten healthy volunteers who have no history of brain vascular disease were enrolled in this study. A cutaneous pain was provoked by isotonic (0.9%) saline injection into intra-dermal space on right lower leg through 24G plastic catheter, and a muscle pain was provoked by hypertonic (3%) saline injection into right tibialis anterior muscle. We used event-related FMRI to measure brain activity during each injection. Visual analogue scale (VAS) was used to quantify pain intensity and unpleasantness, and pain quality was assessed with several verbal descriptions. Pain unpleasantness rating was higher in the muscle pain compared to the cutaneous pain, despite the same pain intensity rating. The cutaneous pain had more acute pain onset than the muscle pain. Pain duration after stimulation was short in the cutaneous pain, but long in the muscle pain. The extent of the painful region tended to be larger with the muscle pain, but there was no statistical significance. Evoked FMRI response from the cutaneous pain showed distinct brain activation in the inferior and superior parietal cortex (BA: Brodmann area 5/7/40), primary and secondary somatosensory cortex (S1 and S2), insula, supplementary motor area (SMA, BA6), posterior cingulate cortex and cerebellum. On the other hand, FMRI response from muscle pain showed distinct brain activation mainly in the contralateral insula. These results suggest that the parietal lobe including the S1 is the essential area for cognition of sharp and well-localized pain conditions such as cutaneous pain, and may not be essential for cognition of diffuse pain derived from muscular tissue. (author)

Polymorphism of myofibrillar proteins of rabbit skeletal-muscle fibres. An electrophoretic study of single fibres.

OpenAIRE

Salviati, G; Betto, R; Danieli Betto, D

1982-01-01

Rabbit predominantly fast-twitch-fibre and predominantly slow-twitch-fibre skeletal muscles of the hind limbs, the psoas, the diaphragm and the masseter muscles were fibre-typed by one-dimensional polyacrylamide-gel electrophoresis of the myofibrillar proteins of chemically skinned single fibres. Investigation of the distribution of fast-twitch-fibre and slow-twitch-fibre isoforms of myosin light chains and the type of myosin heavy chains, based on peptide 'maps' published in Cleveland. Fisch...

Effects of mouthguards on vertical dimension, muscle activation, and athlete preference: a prospective cross-sectional study.

Science.gov (United States)

Gage, C Colby; Huxel Bliven, Kellie C; Bay, R Curtis; Sturgill, Jeremiah S; Park, Jae Hyun

2015-01-01

Mandibular repositioning and subsequent neuromuscular signaling are proposed mechanisms of action for commercial mouthguards marketed for performance enhancement. A prospective cross-sectional study of 24 healthy adult weightlifters with normal occlusal relationships was designed to determine whether 2 self-fit performance mouthguards; a custom-fabricated, bilaterally balanced, dual-laminated mouthguard; and no mouthguard (control) differed in their effects on vertical dimension, muscle activation, and user preference during a 75% maximum power clean lift. Each subject was tested for each of the mouthguard categories: Power Balance POWERUP, Under Armour ArmourBite, custom, and no mouthguard. Interocclusal distance was measured at baseline and with each mouthguard. Mean and peak activity of the anterior temporalis, masseter, sternocleidomastoid, and cervical paraspinal muscles was measured during sitting and during a 75% maximum power clean lift. A mouthguard preference questionnaire was completed. Analyses were conducted to determine whether interocclusal distance differed among mouthguard type and to examine the effect of mouthguard type on mean and peak muscle activation during the clean lift. Interocclusal distance was affected by mouthguard type (P = 0.01). Mean and peak activity of the anterior temporalis and masseter muscles and mean activity of the sternocleidomastoid muscle differed among mouthguards (P < 0.05). Mouthguard type did not influence muscle activation of the cervical paraspinal muscle group. Overall, the Power Balance mouthguard produced more muscle activity. Participants preferred custom mouthguards nearly 2:1 over self-fit performance mouthguards (P = 0.05). Participants perceived that they were stronger and were less encumbered when using a custom mouthguard during submaximum power clean lifts.